I just finished watching the AEC launch webcast from Friday and reading the press kit materials (available on the same page). One of the questions at the end was whether or not Civil 3D 2010 would be 64-bit native. While they did have some technical issues that prevented a clear answer on the webcast, let me throw out two bits of data for your speculation:
1. Access mdb format is essentially a dead format, and will likely never be ported to 64-bit system. Survey and points databases are historically mdb files.
2. Map 2010 was touted at being 64-bit ready in the PR kit. This was a common request from Map users, so when they addressed it, Autodesk made it a selling point. Good business in my estimation.
Since there was no mention of a change in the survey format, and there was no specific mention of a 64-bit C3D as a primary selling point…I’ll let you connect the dots.