I somehow doubt this game will be able to take advantage of more than 4GB of RAM, which is one of the only benefits to going 64-bit.
They already can do it on some levels, just not in any of the graphical builds because of Havok. Map size is limited by ram, and it isn't as simple as "limited to 4GB of ram". Certain variable peramiters must be set with small restrictions in 32-bit. A 32-bit machine for example just cannot function with a map landscape over a certain size. (64-bit has the same problem, but the size is far greater than any current systems can even try to reach)
And saying its limited to 4Gb isn't even accurate, its really limited to 2GB, just windows XP has a work around to give access to up to 4Gb. And 2Gb, or even 4 Gb, of space isn't that much space anymore. Its a serious limit in terms of what kinds of textures, filters, animations, and other storage intensive files. You can see texture limits in the current next gen consoles rather well. The PS3 for example is a supercomputer by the defitions of "supercomputer" at the time of its launch. However limited memory causes it often faulter in environments with particularly complex textures.
Point is, ChongLi, yes, they could have benifit from more than 4GB of RAM just with a bit of tweaking from the buildy were showing at PAX.
@pigeonpigeon: I would think there would be a way just to have a process running at 64-bit and have the graphics handled by a second system running as 32-bit. But its one of those cases where "I don't know how you would do it" so I wouldn't expect it. I can imagine internal system sync nightmares coming from such an attempt.
