This isn't everything from 3.3.3, but there's some interesting things. First off is three new mounts. Second, the child prince is getting a grown up look (either for future use or he's actually growing up). Third, new pets.
The first new mount is another tailoring pattern off of a guy (Frozo) who will now sell all the stuff you used to grind (eternals, frost lotus, etc) in exchange for Frozen Orbs (that drop in heroics).
The other two mounts are the Blazing Hippogryph (above) and a dumb white kodo, both of which are (currently) TCG. Since the Blazing Hippogryph is cool, I expect it to break $100 on ebay, easy. The Spectral Tiger breaks $1,000, and the Rooster breaks $200 so my estimation might even be low.
Two new pets: Frigid Frostling and Blue Clockwork Rocket Bot. I think I'm a little sick of blue icy things. I get that it's a theme, but really guys. Does everything have to be frosted?
Of course, there are the honor changes I mentioned before, and improvements to the AH that I'll let you discover on your own.
You'll be able to queue for Holiday Bosses in LFG now, but I'm not impressed until I know if they'll take available summons into account. I envision a lot of people complaining if they don't.
They also seem to be setting up world events to usher in Cataclysm. This could just be the pre-event setup, though, so don't get too excited. I doubt they could top turning into zombies.
And, of course, this is not all the info yet. Boubouille says "This news post will be updated multiple times in the next hours! Stay tuned!"