Same problem. I and all my friends on this server have too this problem. We play a few hours and we get freez, in the longer term, we can play again but again for a few hours before we get freez. I think this problem must have much more players. It would be nice if someone fix it.
First try deleting your WTF folder in the WoW Directory and your cache. If that doesn't work reinstall WoW, there could have been an error while installing, try running the WoW repair function before reinstalling.
Bloodreaper it cant help. I did repair, deleted cache, turned off addons and i tested play on other computers (without addons), but my character was still at freez. Its 100% server bug. Player cant do anything.