This is great news and offers another opportunity for Dems to pick up a GOP held seat. Attorney General Madrid D-NM, might be a good candidate but she lost a close race for a House seat in 2006, in a year in which Dems picked up 31 House seats.
Unfortunately with Mike Huckabee's pathetic fundraising numbers, the odds are increasing that he could run against Pryor in Arkansas. Of course if Hillary's the nominee, advantage Pryor since Sen. Clinton's crushing all Republicans in AR.
It references Democratic Congressman Udall running and speculates as well on two Republican congressman running, one of which is Congresswoman Heather Wilson, who defeatd Attorney General Madrid last fall in a hard fought battle.
A Udall-Wilson match-up could be interesting for the Senate seat - Wilson has some baggage over the firing of the US Attorney in New Mexico, which I suspect is the main reason Domenici decided to retire. And it would give Madrid a leg up in running and winning Wilson's seat.