blood elves(horde) and random alliance(not chosen), outlands, level 70, and lots of other neat stuff, flying mounts( only available in outlands )
well ill just copy it from blizzard.com
An increase in the level cap to 70
Two new playable races, including the magical Blood Elves
New starting zones in Quel'Thalas and beyond
The entire new continent of Outland, reachable through the
Dark Portal
Many new high-level dungeons to explore in Azeroth,
Outland, and elsewhere
New flying mounts in Outland
Many new and dangerous monsters, including epic world
bosses
Hundreds of new quests
Hundreds of new items
A new profession: Jewelcrafting
Socketed items
And much, much more...
jewelcrafting is basically making socketed items. Like in diablo 2. And I think he include every leaks that is right now. One thing for sure though: there are going to be warrior available for blood elf. Lol every race can be warrior.