Various sites have posted this new info, but so far I've found that MMO Champion has a useful round-up with sources, here: http://www.mmo-champion.com/content/1790
Some of the information is a bit surprising: the Path of the Titans feature has been removed and replaced with a new level of glyph, which means that Archaeology will be more akin to fishing or cooking rather than an (effectively) required skill for progression.
In addition, guild leveling has been slimmed down a bit with the removal of guild talents and more emphasis on gaining reputation within your guild. Check out some of the possible rewards, though: tabards, mounts, heirlooms, guild tabards for your mounts ...
And it looks like Blizzard is concentrating more heavily on the look, feel, and story in the new zones as well as changes to progression and questing in old zones. For example, Cataclysm has over three times the new quests as Wrath of the Lich King did. As an inveterate leveler, I am very excited to see the new quests!
Oh, and there's information on raids and stuff. I didn't read that part, though so I'll leave that to you guys.
