I think several points that have been brought up in this thread are worthy of some discussion.
It is, of course, hard to argue with Shipwreck's and RedCorvette's observations that, in the grand scheme of things, what's happened to the Cutty Sark is a relatively minor event. I can easily understand why, for instance, somebody who lost a family member in Iraq that day doesn't think a fire on board an 1869 clipper ship was a matter of much importance. Thank heaven nobody was killed or injured in the fire.
In the field of artifact preservation (which is, in essence, what we're talking about here) the distinction between a genuine artifact and a reproduction is more than sentimental. The artifact itself is a representative of the time and circumstances in which it was made, and of the people who made it. Replicas have their uses - invaluable uses in some cases - but they just aren't the same as the real thing. And when an artifact (e.g., Grampa's hatchet, which has had two new handles and three new head since he carried it at the Battle of Lexington) undergoes restoration and conservation, it's almost inevitable that the people restoring it will inject something of their own time and circumstances into it.
An excellent example is H.M.S. Victory. The planking on her hull doesn't look much like it did in 1805. The species of wood is different (I think; maybe I'm wrong about that). The method of fitting the planks together is different. (The old "anchor stock" pattern is nowhere to be seen, and the modern shipwrights apparently didn't use traditional caulking methods.) The wales, which originally were huge timbers fastened directly to the frames, are now thin layers of timber fastened to the outside of the planking. The lower masts are steel tubes, supported by steel rods that penetrate the hull bottom and are embedded in the concrete of the drydock. The list goes on and on. The Victory is a priceless artifact, and the various deviations from her 1805 configuration were made for perfectly legitimate - indeed, in many cases, unavoidable - reasons. (The expenses of materials and labor really make an absolutely accurate reproduction of a ship like that impracticable.) I intend no criticism of the people responsible; they've done an outstanding, conscientious job within the parameters that reality has imposed on them.
But the Cutty Sark, until recently, was, with some obvious exceptions (e.g., the airports that were added to the 'tween deck spaces by the Portuguese), the "real" Cutty Sark. I gather some criticism of the people who maintained her over the years has been offered recently, but generally speaking I think they did a fine job. The original hull planking, for the most part, lasted almost 120 years. That's about as long as can reasonably be expected.
It was inevitable that, if the ship was not to fall apart, much of her fabric was going to require replacement eventually. As I understand it, the present restoration project was scheduled to replace many major components of her - even before the fire. That was regrettable, but it was bound to happen eventually. How much additional replication of original parts will be required because of the tragedy remains to be seen. I have the impression, though, that the people responsible for the research and restoration know precisely what they're doing; I'm confident that the Cutty Sark that eventually goes back on public exhibition will be as "accurate" as scholarship and technology will permit - tempered, undoubtedly, by the realities of money.
As I understand it, the possibility of floating her and sending her to sea again was considered early in the restoration planning - and rejected, for good reason. Experience has established that floating an historic ship, especially in salt water, is one of the worst ways to preserve it. The hull tends to hog, leaks inevitably develop over time, and all sorts of corrosion and other processes take place faster than they would if the ship was on dry land. (A couple of weeks ago I had a conversation with two of the curators of the U.S.S. North Carolina. She appears to be afloat, but in fact sits in the mud across from downtown Wilmington. She's old enough now that leakage and various sorts of corrosion are becoming significant problems. I don't know what, if anything, will be done about them; the possibility of hauling her into a permanent drydock seems remote.)
Furthermore, to send an old ship out to sea in this day and age requires all sorts of compromises in order to comply with the law. The Coast Guard (or its foreign equivalent) requires that such a ship carry numerous devices related to safety and navigation. (Imagine the Cutty Sark with a radar screen at her main masthead and a couple of diesel-powered lifeboats hanging from her davits.) The requirements get stricter if the ship is going to carry passengers. And some further compromises with authenticity are almost unavoidable in the name of good sense, even if the law doesn't mandate them. (The first Pride of Baltimore might well still be around if she'd had modern hull compartmentation. Do we really want that for the Cutty Sark?) And operating a ship on the high seas inevitably involves a certain amount of risk. It seems like we hear about vintage, flying historic aircraft crashing every few months. (Remember when the RAF's Meteor and Vampire ran into each other?) I personally do not want to read that the Cutty Sark or the Charles W. Morgan has gotten sunk, like the first Pride of Baltimore.
My spine tingles as much as anybody else's at the sight of a great sailing ship under sail. But I share the feelings of Captain Tyrone Martin, former commanding officer of, and reigning expert on, the U.S.S. Constitution. When she got under way under sail for a few miles some years ago, he expressed decidedly mixed reactions - and urged the Navy not to sail her on a regular basis. I believe the phrase he used was: "The old lady isn't ready for rollerblades." Neither is the Cutty Sark - and she never will be.
Some people in the historic ship community don't believe in full-size replicas. Those people argue that the pool of money for such projects is severely limited, and that the available funds ought to be spent on preserving the real things. My personal opinion is that ship replicas, if they're well-researched and well-built, serve some very worthwhile purposes. I don't think the Cutty Sark, or the Constitution, or the Morgan, or any of a couple of dozen other historic vessels, should ever go to sea again. They're priceless, irreplaceable artifacts, and they deserve to be restored as accurately as possible to their historic configurations - and exhibited to the public in the most stable environments possible. But I also greatly enjoy going on board, and watching, well-done replicas like the three Jamestown ships, the Mayflower II, the Elizabeth II, the new Endeavour, and the Batavia. They offer their own forms of education: the guys who've sailed the Susan Constant know a great deal more about seventeenth-century seamanship than could ever be learned from contemporary documents, and the reconstructed Greek trireme Olympias has generated a major scholarly rethinking of galley warfare. And they provide modern ship lovers with at least a glimpse of what the old ladies must have looked like. If somebody wants to build a replica of the Flying Cloud, and can fund the project without taking money away from any historic ship preservation projects, he'll have my enthusiastic support. But please keep the Cutty Sark in drydock.
Sorry to go on so long, but I think this is a pretty important topic. There's my two cents' worth.