Reply to Andrei,
In my opinion, it's not application pressure that drives 64-bit machine adoption, now or in the near future. It's RAM price, availability, and usefulness. A 32-bit machine cannot gainfully have more than 4GB of RAM, period.
IIRC 32 bit Intel chips can address more like 64GB of RAM (I can't find the ref but I seem to recall about 4 extra address bits). It's just virtual address spaces that are limited to 4GB (or 2-3GB after the OS takes it's pound of flesh)
As pointed out, only a few apps need anything near 2GB of RAM per process.
That's an awful limitation in wake of increased OS and application demands and falling RAM prices. So people don't migrate to 64 bits just because a whole bunch of "gotta have the fanciest stuff out there". They migrate (often without even knowing it) just because they want more RAM. And they want more RAM because machines with more RAM often run smoother and faster. Andrei
