The download area shows the 32-bit version. However it will install and run just fine on 64-bit machines. This is just saying that the program itself isn't truly 64-bit....yet.
If you are waiting for the DVD to arrive in the mail, that will be starting to ship this week April, 17th 2009.
The second thing I want to mention is for network installs. There is no more Network Activation Utility. You now must either A) login to register.autodesk.com or B) Call 1-800-551-1490 (press 1 para Englais). In either case, you must know your server MAC address and your product serial number/group number.
If you've never done an online registration before - registration only takes a moment. You'll need your company information and e-mail address to create an account.
Lastly, I want to mention the Portable Licence Utility...or lack thereof in 2010 products. All stand-alone license transfers now go through the online License Transfer Utility found in Start > Programs > Autodesk > AutoCAD Civil 3D 2010.
Believe me - this is much easier. You don't need to have the product installed on both computers at the time of transfer anymore. Nor are there any computer ID numbers to deal with anymore. You essentially upload the license to an Autodesk "holding area" and pull it back down when you need it. Yes, you do need internet access on both machines - just for transferring.
In all cases, if you have trouble with registering your new software or transferring licenses, don't forget to call your friendly neighborhood reseller for help!