Is he drunk...

[BBboy20]

or just being himself? (http://www.youtube.com/watch?v=AxvTOxeeFSA)

[Caribou]

It doesn't seem too much unlike his normal self, for as far as you can call him normal.
But they also might've been having a drink in the studio. They did before, when the album was released and they put these weird clips on youtube of Thom writing stuff down and talking to the camera and nearly falling over...