The word on the TV street re: Ann Curry is that they 'like her where she is' as news anchor and she recently signed a new contract to remain there. The recent deal was sweetened by some new responsibilities at NBC's Dateline so they don't really have an incentive to move her.
Here's some info from TVWeek
Curry, 49, has been the "Today" news anchor since 1997. Given this role, the fact she's not seen as the slam-dunk favorite to succeed Couric may be telling. NBC recently gave her another big job, as co-anchor of "Dateline NBC."