The Core 2 brand refers to a range of Intel's consumer 64-bit dual-core and MCM quad-core CPUs with the x86-64 instruction set, and based on the Intel Core microarchitecture, which derived from the 32-bit dual-core Yonah laptop processor.
The Core 2 brand was introduced on July 27, 2006 (WIKIPEDIA QUOTE)
Thanks for your reply's Martin, but you (and the confirmations of others who didn't know) slowed me down quite a bit, and had me thinking that I wanted the newer model for the $250 more, seeing that you said that I didn't have the 64 bit. Seeing I have the MA590, it already qualifies as the above. So I can fully run in 64 bit with the MA590 and Leopard.
As for your last comment "Also, only software that is optimized for 64-bit processing will truely use 64-bit processors to their fullest ... and that's not much software at the moment." , I think that's all the more reason to get 64 if it's convenient! Apple is merely setting the trend in motion for what is to follow (it seems like they kind of do that these days -- ie. iPOD, iPHONE, iTUNES etc.), so why not try to get something NEW, rather than OLD if the opportunity is there? It matters not that few 64 apps are out there now, because they will be soon enough, and meanwhile I'll be enjoying the speed difference along with my new RAM for $99/Gig (not $200/Gig like someone ELSE told me).
Thanks for your help anyway.