As you are probably aware, next Tuesday will mark the launch of one of the biggest games of the year, Gears of War 3. In order to ramp the forums so they are ready for launch, we will be upgrading them sometime today (9-14) or tomorrow (9-15).
The forums will be down for at least a few hours, and there will be a few noticeable changes and some missing features/themes when the forums return. We'll be working to return everything over the next few weeks.
Thanks for your patience!