We'll if you've watched the 2010 AEC Product Launch Webcast, you'll notice that one of the questions was unable to be heard. The question I'm referring to is:
Q: If Map 3D 2010 supports 64-bit operating systems, will Civil 3D 2010 also support 64-bit systems instead of running as a 32-bit program in 64-bit environment?
Now this question is of interest to me because I use Vista as a 64-bit Operating System at home. I was a bit disappointed that the answer indicated that it wasn't going to be included in this release.
A: Civil 3D 2010 does not take full advantage of 64-bit systems at this time however it is a high priority for future releases
Hopefully 2011 will bring a Civil 3D that runs natively on a 64-bit system.
If your looking for more information on Civil 3D 2010 I'd start looking for other blogs posts later this evening. I suspect James over at Civil3D.com will be one of the first with posts regarding the new product.