This is their first ever patch (in live). Even though WoW has been around for 7 years they still have unexpected problems during maintenance occasionally (and not just on patch days). If this is resolved within a few hours you cannot say they're not doing a good job when some other games that have been around for years and have had a lot of time to refine their patching process etc. still can't deal with problems that fast. They're working on it, that's all you need to know. You'd have reason to complain when the servers have been offline for days.