It's a new version of the old old TARDIS, kind of a nice hybrid between the two.
And as for The Doctor and his appearence, I think it will grow on me. It's far more Doctor-like than Tennants purposely attractive modern look. The Doctor is meant to be an eccentric character who isn't quite sure where he's going and how to dress for the occasion... so bow tie and tweed makes perfect sense really!
Also I feel he's quite liked how he dressed as a teacher when Mr. Smith, as it's very similar to his look when concealed in the Fob Watch...
Yeah we don't know exactly what it is, but we do know there WILL be a new interior due to the current one being naff in High Def. You'll probably see it missing from The Waters of Mars [or whatever anagram you wish to call it] just like it was from Planet of the Dead.