This would definately be nice if they made 64 bit support from the beginning. As far as I know nothing have been anounced yet. But I did a google search and http://www.battlefor...ort-64-bit.html showed that there was evidence that there might be a 64 bit for the release. But as I'm not a member of the site, I can't see the photo he used as evidence.
But they are testing it on WoW now, so there is a good chance that they atleas will implement it eventually in D3 if not from release.
Yay! I have 8gb RAM so 64 bit would be really awesome