The Mac versions of Adobe's products are all 32-bit. None are coded for 64-bit. When it comes to both Mac and PC software, very little has any 64-bit stuff in it.
Sure, the MacOS has some big chunks recompiled to handle 64-bit software. However, the OS is mainly tuned to handle 32-bit stuff. It has to do that. Otherwise you wind up with a "server only" solution like Intel's Itanium platform where if you want 64-bit EPIC coded apps, device drivers, etc., you're going to have to write them yourself. Not too bad a deal if you own a Fortune 500 company with a top flight IT and development department.
A few PC games have 64-bit coding chunks to take advantage of certain AMD processors. Those functions are making specially designed direct calls to hardware, not really anything based on the OS itself.
Certain flavors of Linux, Sun Solaris, IBM's AIX, etc. operate in 64-bit mode, but just like Intel's Itanium line (and the 64-bit version of WindowsXP specifically made for Itanium CPUs), you are usually stuck with only running 64-bit software and hardware on them. For most computer users that situation would really stink.
For now, the whole 64-bit thing is a very overrated thing. The only real advantage any regular end user will get out of it is stuffing a computer with more than 4GB of RAM. That much RAM is still pretty darned expensive.
Even if WindowsXP 64-bit Edition ships in March (the version written for regular Intel Pentium and Xeon CPUs), I won't be looking at loading it on any PC I have anytime soon. Until all the apps I use are recompiled for 64-bit (especially those with antiquated security dongles), I'll consider 64-bit more of a liability than a plus.
Just thought I'd point that out to prevent this from turning into some silly Mac versus PC thread. Applications, such as Flexi or Photoshop, are the only thing that actually matters in that game.