Of course, it's NOT available. It's been YEARS since XP 64 came out, and now with Vista 64, we still don't have a 64 bit version of FLASH. Why do we want one? So that we could use the 64 bit IE and not the 32 bit one.
Here's the ADOBE FLASH 64 link: Flash Player support on 64-bit operating systems
Hit that site as MANY times as you possibly can, and in the FEEDBACK (right side of the screen), yell at them for not coding this! Do it repeatedly. Perhaps someone with their head up their ass will wake up and start a movement to code a 64 bit version.
VOTE FOR YOUR 64 BIT!!!