Today after work I stopped by the office, which, despite not being listed ANYWHERE online, I found. There I was welcomed by two staffers who were from Virginia originally, but worked for Obama in New Hampshire and South Carolina. They told me their plan to engage Virginia with a grassroots, field-based campaign (although that does not match with the fact that they did an ad buy in all three Feb. 12 states).
To confirm that Senator Obama was the first major candidate with a regional office in Virginia, I called the campaign of Senator Clinton, who has no Virginia office beyond the Arlington Headquarters, Senator McCain, who has no Virginia office beyond the Arlington Headquarters, and Governor Romney, who didn't pick up the phone.
The address for Obama in Richmond, by the way:
808 N. Hamilton Street, Richmond, VA
It's a small building with Obama signs in the windows, you can't miss it.