It's started.

Save when you purchase your tickets on AA.com by October 3, 2007. Outbound travel is valid October 29, 2007, through March 13, 2008. All travel must be completed by April 12, 2008.

Fares to London:

ORD from $420+ ($586 all in)
DFW from $464+ ($615 all in)
JFK from $355+ ($498 all in)
BOS from $358+ ($517 all in)
LAX from $517+ ($614 all in)

All in prices found using "dates flexible search" for 7 nights in Jan 08.