Unfortunately, Brewfest bugs and issues continue to plague the Warcraft servers. Drysc is keeping an open post on Brewfest hotfixes on the WoW forums; it's probably your best source for the most recent info.
I'm most sad about the fact that they disabled the Dark Iron attacks. The screenshot above gives you a picture of what they looked like, as well as a glimpse of the /wave related visual effect with the beer mugs that caused the issue. (The number of people spamming /wave outside Ironforge actually crashed Eastern Kingdoms on our server last night, to give you an idea of how bad it was.) Hopefully they'll come up with a fix; while they lasted, the DI attacks were one of the funniest, most chaotic events I've ever seen in WoW so far.
Other changes and known issues: the "Bark For..." quests are bugged on many realms, but as soon as they get unbugged, they'll be rewarding players with 40 Brewfest tickets instead of 15. Also, the Eyesight Enhancing Romance Goggles will now be permanent instead of temporary! So that's at least one awesome thing amidst all the disappointment.
Update: The BRD quest from the Dark Iron Plans may also be bugged.
Additional Updates (10/5): The "Bark For..." quests should now be working for everyone. If you're still having trouble, check to be sure you don't have a failed version of the quest still sitting in your log. Also, it's been confirmed that "Pink Elekks on Parade" is only available to players with tBC installed. Unfortunately, we still have no ETA on the return of Dark Iron dwarf attacks or whether the ticket rewards will be increased some more to make up the difference.