I agree wholeheartedly with what Gino's said.
Firstly, the Apache is JUST hitting the 20 year mark. The 6th Cav fielded their first Apaches in late 1984. Second, there is no need to replace what works incredibly well (I've even heard an Apache pilot or two say that the D model wasn't even necessary!) Most AH-64A's in service are under 20 years old. As they hit that 20 year mark, they will be sent back to Arizona to the Apache plant and will be remanufactured (read COMPLETELY rebuilt) into AH-64Ds. The majority of AH-64Ds that are in Iraq are less than 5 years old.
The Comanche would have been a cool looking helicopter but no less vulnerable to unguided ordnance than anything we've got now. Its stealth capability didn't hide it visually, and therefore it was still vulnerable to RPG and Small Arms fire, just like the rest of the helo fleet. It didn't make sense on the modern battlefield.
The problem nowadays is that while our technology and capability keeps increasing, our enemies have gone increasingly low-tech. High Tech may not be the answer, particularly in the current conflict. Doing more with the equipment on hand and using the money saved from R&D programs (like the Comanche) is going to keep our helo fleet mission capable for many years to come, instead of fielding a multi-billion dollar turkey that looks cool, but gets shot down just as easily as a current helo.
stepping down now...
Gino,
Artilleryman, huh? I've got a few buddies headed your way, but I'm hooked on the Aviation thing. I'll be happy to spot for you anytime though! Keep an eye out for a 2LT Nate Moore. He's in MLRS. Sharp guy and a good friend, just finished AOBC a few months ago.