I didn't realize that SL automically boots in 32 bit, even on the new iMacs. I have a core i5 with 8 gigs of RAM. Assuming I boot in 64 bit mode today, will my computer now utilize all 8 gigs? Was it only using 4 gigs in 32 bit mode? Also, will some applications not run if I boot 64 bit? Any other info is greatly appreciated.