Woo finally registered on the forum. I'm with Iain, this does seem a little odd, as far as i know, wotlk is still on closed alpha testing. I guess its possible that it could have been leaked/hackedfor a private server already, or whatever the term is, but you really wanna be careful about where u advertise that fact. If you've seen the terms and conditions of their closed testing phases it basically allows them to sue you for as much money as they deem fit, with no proof that you've actually caused them any damage.
Those pics could quite easily be a normal client with a model changed i guess. That and i'm pretty sure you cant get to 80 even in the alpha/beta yet, but maybe that can be hacked too i dunno. Soz I'm just naturally skeptical :p
Havin said that I'd be happy to see more pics and see whether i reckon they're real or not

maybe some of the new areas, deathknight ui, new abilities, that type of thing.
Edit: just noticed this thread is pretty old, oops :p