As much as i want to see new models i dont think there will be any new info.
Most likely in typically Blizzard fashion, they got 75% done with the new models and then decided to scrap them all and start over.
Trolls - we've seen them in ToT Raid.
Orcs - Thrall/Garrosh.
Night Elves - Well of Eternity dungeon.
Human - Varian/Jaina(?).
They will be more than polished, they will be reanimated to have more personality and expressive movement than they already do, on par with the Pandaren and Goblin and Worgen models. Thrall and Garrosh are closer, but your other examples are just subtle tweaks.
If you like my draw-rings. http://yig.deviantart.com/
If you can't find them for some reason beyond that page. http://yig.deviantart.com/gallery/
WOW screenshot and concept art gallery http://smg.photobucket.com/user/evilknick/library/WoW
I could imagine we might be lucky enough to see a least a little something, but not gonna get my hopes up.
I can't recall how they said they are approaching the revamps but say they have teams doing every race, as opposed to one race at a time, they arguable could have one of each particular race/gender complete to showcase which would be great for a preview. If not it'd be nice to see everything they've got done so far for critique.
If it's not an elf, leave it on the shelf.
Night Elf Liberation Front N.E.L.F.
Something mean about trolls.
Or maybe its 25% of every model in the game.
With player models completely finished.