Actually, from the news reports I've read, most of the money for the next five years is coming from a reallocation of resources within NASA. Future administrations from whatever party is in office will have to decide if the funding should continue, and I'm sure that will be based on the progress at the time.
The shuttle is decades old and was simply not designed to leave Low Earth Orbit. Hence the need for a new space vehicle. Heck, even if the plan was simply just to carry on with LEO projects for the next 20 years, we would _still_ need to replace the shuttle.
For the past three administrations, NASA has been losing some of its vision and technical leadership. Now, hopefully, that will change and the rewards for us (maybe not short, short term but in our lifetimes) will be huge.
As an IT professional for the past twenty years, and as someone with a family member who actually was involved in the Apollo missions, I for one am glad to see this plan put forward and NASA basically put on notice. Sure, the announcement has a political element, but it's ticking off as many folks as it is gaining supporters. Agree with the new space policy or not, you do have to admit that the President took a risk and made a decision (which in this case was recommended by the Challenger Commission). I wish leaders from both parties could do that once in a while. ;-)
I also agree with the prior post about the book "Case for Mars." Excellent read.
We all have to remember that exploration and the benefits gained from it will take time to realize. Just because I won't see a new super duper glue polymer or whatever on the Home Depot or LHS shelves as a result of the new Moon/Mars missions tomorrow does not mean that they should not eventually happen. As a society, we've become too engrossed with demanding instant answers and instant results.
As an aside, a local company up here in the frozen foothills of New York State announced today that they plan to DOUBLE the size of their work force for the 2nd time in one year. This company developed a polymer or some sort related to new heat shield technology that will make tiles obsolete. The company's CEO was on the news tonight saying how this new space initiative has already landed it a contract with NASA and that they hope to open additional facilities here in the next 2-3 years.
In any event, good discussion here. And, I am looking forward more than ever to the concept models. :-)