gribble
Explorer
This is exactly the sort of change I expect, and this is something that should result in a very short downtime. Certainly one measured in hours (at the most) rather than days. And even that "outage" should be in the form of a read-only period not a complete outage.I recall reading during the Gleemax discussions that WotC's website and DDI are using a Microsoft platform, while vBulletin is Linux-based. So maybe they're moving their messageboards to a Microsoft-based platform.
For the record, I think the most likely explanation is poor process/management. I'm a coder myself, so I wouldn't want to blame them...

And by that I don't necessarily mean "WotC Management is the suxxor!!!11!one". As Umbran pointed out they might be operating under constraints - usually budgetary or related to the experience or number of staff - which mean they can't do things properly.
As others have pointed out we'll probably never know the details, but it is an unusually long period of outage. I guess I just wanted to back up the opinion of Ulorian and others in that regard. Seems like he's taken a bit of stick for his views which (even if they weren't expressed in the best way), are 100% accurate IME.