Here's a quick heads up: It looks like tomorrow's maintenance will be lasting from 3am PDT to 11am PDT, for a total downtime of 8 hours. Anyone who usually plays during that time, it looks like you'll have to find something else to do (such as read WoW Insider).
An 8 hour downtime sometimes heralds a new patch, and we do have patch 2.4.3, which features land mounts at level 30 and a Cheat Death nerf, on the PTR at the moment. Then again, there was a new version of the patch applied just a few days ago, which could mean they'll want some more testing time, so we can't say for sure if it's coming.
Right now, I'd say that there's an even chance that we'll see 2.4.3 going live tomorrow, but either way, stayed tuned to WoW Insider. We'll let you know as soon as we know for sure.