Because Skyrim was 32bit, it could only use 3.1 gigs of RAM. 64bit will not only make the game more stable but allow us to use much more ram. I think (and hope) this means we can run as many scripts as our PCs can handle. There are several mods I can't use because I add lots of NPCs to my game and mods that had 'cloaking scripts' for each NPC (such as Footprints, Wet and Cold, ETC.) would cause script lag or even crash my game. 64bit could mean not only that we could run many more script based mods but more advance mods would be possible.