Is it just me, or did that trailer feel xenophobic in a way Borat sketches usually don't?

Perhaps, but I'm looking forward to the Borat movie for the American setting, and not for its mockery of Kazakhstan (which may not even be in the movie much at all).

Was it just me or did Borat's accent sound different? I am being serious.

I had just watched a clip of him on Conan before watching the trailer and his accent did sound different. Maybe when he's more scripted he does it better/differently.

It does sound different. I doubt the Kazakshtan stuff has much to do with the film. Perhaps it's will be a bookend to the film, which means that it must have been directed by Spielberg.