You guys need to learn how to do maintenance with servers up. Having them down for eight hours a week is quite irritating.
It's mostly because it's only technically
maintenance. We're pushing a new build so that beta testers like you have the most recent stable build to test in, also so we can see the build in closer-to-live conditions.
As we get closer to the release of 5.0.4 (August 28th! http://us.battle.net/wow/en/forum/topic/6308782635
) these are going to be happening with increased frequency. I understand that can be irritating but ultimately it's all to make sure the patch release and the following expansion are as awesome as possible.