To sum-up, here's some of the bullet points covered in the reveal video:

A new world to explore/destroy (depending on your bent): Draenor

The chance to build and upgrade a garrison - WoW's version of in-game housing - that you can upgrade and customize to suit your needs, just like you would in an RTS.   Its even been said that you'll be able to stake your plot anywhere you want (though this may be subject to change towards more faction-related territories).  Garrisons will host followers, gather resources, and grant buffs and/or boons to the "lord of the manor" - i.e. the player - that take the time to trick it out.  Crafting options other than what the player currently has will be open to them, and it's been said by the development staff that even EPIC TIER gear will be craftable via garrison followers.

Updated character models!  Yes, the polygons will be strong in this next update, adding depth to character appearance that's been sorely lacking from a title that didn't exactly have cutting edge graphics when it first launched.

An increased level cap to the tune of 100!  Additionally - and frankly I saw this trend coming from leagues away - you can boost either an existing character or a brand spanking new one to level 90 to jump into Draenor right from the get-go!  So far, this level-boost service is reported to be a one-character-per-account deal (i.e. buy Warlords of Draenor, get the boost for one toon), but I predict that will change; either to one character per server, or it will become another paid service so players can throw even MORE of their cash at Blizzard.

As usual, there will be new zones - pvp world zones and otherwise - new dungeons, new monsters, and new raids in the xpac.

And, the ultimate draw for WoW - moar phat lewts!  Yes, new gear, rewards, and items will be coming with the next expansion.

All this... and there's still a FULL DAY of Blizzcon left!  Wooo!