Thanks for the heads-up, Kris. That's a bummer. Is it both the WMT training site and the Connection forum, or just the forum? We can definitely pass this on to the right people on the Windows Mobile team, who will likely be able to reach out to AT&T from their end...
As for the mobile version of the forum: This has been high on our to-do list for a while, and we're just now trying to estimate what it would cost for us to build it. At the moment, however, it's looking like it won't happen any time soon - it turns out we'd need to do quite a bit of engineering work from scratch (expensive!) to enable all the important forum functionality while using mobile-optimized code.
So at the moment, the best option is one of the more recent browsers (IE in WM 6.1 works great!).