http://blog.washingtonpost.com/thefix/20 07/10/sen_pete_domenici_expected_to.html #comments

As long as Cillizza's sources are solid, NM has become a top-tier pickup opportunity.  Rep. Heather Wilson is often mentioned as Pete's successor, but the US Attorney scandal may have scuttled that career path.  The other major R option seems Rep. Steve Pearce, who is significantly more conservative (think Bob Schaffer in CO).  If Wilson were to run, her seat would probably become lean-Dem, while Pierce's seat is likely GOP (though not  safe - his opponent's numbers were in the 40's last election IIRC).

For the D's, the top two options seem to be Albequerque Mayor Martin Chavez and Rep. Tom Udall.  My personal preference would be for the latter; Chavez is quite conservative and had previously endorsed Domenici.  But either guy would probably have the edge over Wilson or Pearce, particularly in this environment.  Cillizza also mentions Lt.Gov Diane Denish, but she seems more interested in Richardson's current job, and fmr AG Patricia Madrid, but she flubbed a debate with Wilson and is considered damaged goods.

The ginormous donkey in the room is obviously Richardson himself, but he doesn't seem particularly interested (given that he's a shoe-in for Veep or State if he weren't to get the nod).

As long as candidate recruitment goes worse than expected, I would rank this as the fourth lean Dem race thus far (after VA, NH, and CO).