Blanche Lincoln (D-inc): 48
Gilbert Baker (R): 37
Undecided: 16
Blanche Lincoln (D-inc): 46
Tim Griffin (R): 37
Undecided: 16
(MoE: 4%)
State Senator Baker and former US Attorney Griffin are both unknown to over half the state, so these numbers aren't too impressive for Lincoln. What's more, her approvals are just 45-40. (Strangely, PPP did not ask for presidential approval ratings.) Still, she has $7 million on hand and will get all the help she needs. And neither of these potential opponents are at anything more than the "rumored" stage yet.
UPDATE: My mistake - PPP released Obama ratings yesterday. The President's job approval is 47-45. Also, Dem Gov. Mike Beebe (up for re-election in 2010) is at 68-20, "the best ratings of any politician PPP has polled on in the entire country over the last year."