Yeah I'm not sure of the 2011/Spring 2012 line myself... Yes, certain things can be moved in advance, and of course I'd expect our gate areas and office spaces will be set up (but not occupied) in advance of the move... but every other move that I've heard of has been a major overnight transition between last flight of the night and first flight next morning.
The reference to a 'new' tunnel is probably a 'new to us' reference to emphasize the new convenience that will be realized for our DL codeshare flights at LAX. I understand that there will be an actual new tunnel leading from the rotunda to out front to the arrivals/baggage claim area (this tunnel is not currently open), a similar tunnel (with TSA checkpoint for entry) has been opened in T5 already. I do not know if the arrivals tunnel in T6 will include TSA checkpoints or if it will be an exit only.
More and more scaffolding and barricades are up as work continues. Lots of behind the screen work being done so no idea what progress has been made, but everything I've seen points to a nice home for AS/QX operations and, more importantly, a huge upgrade in facilities for our passengers.