Wowhead is where I usually go. Just pop over now and again throughout the day to see what news is up. When they actually release notes about there being noted hotfixes, Wowhead is pretty timely about getting them up.
Of course too, you can check the main thread that gets updated over in General Discussion, should you choose. But having to dig through it and be faced with all of the joys of GD, you’re getting the same thing over on Wowhead without all of the excess chatter.