I am a Tab lover, so I am not complaining.
If Xenforo had the ability to add tabs ..... I'd say this is a good idea.
Not displaying Logout on a mobile device via Responsive design seems like a good idea.
I'd say moving [Logout] is a good idea.
I am just used to seeing the word Log Out in the top right area since the vB3 days.
http://www.vbulletin.org/forum/
While on the topic, vBorg is still on vB3. /Fail.