Research 2000 for Daily Kos (9/14-16, likely voters):
Elizabeth Mitchell (D): 34
Les Otten (R): 28
Undecided: 38
Elizabeth Mitchell (D): 35
Peter Mills (R): 15
Undecided: 50
Elizabeth Mitchell (D): 35
Matt Jacobson (R): 14
Undecided: 51
Michael Michaud (D): 33
Les Otten (R): 29
Undecided: 38
Michael Michaud (D): 34
Peter Mills (R): 15
Undecided: 51
Michael Michaud (D): 34
Matt Jacobson (R): 14
Undecided: 52
Steve Rowe (D): 30
Les Otten (R): 31
Undecided: 39
Steve Rowe (D): 31
Peter Mills (R): 15
Undecided: 54
Steve Rowe (D): 31
Matt Jacobson (R): 14
Undecided: 55
(MoE: ±4%)
Research 2000 polled Maine to get a sense of where the anti-gay marriage initiative on the statewide ballot in November stands. The poll finds the initiative passing (where "yes" = a vote against gay marriage), but by a narrow 48-46 margin. As one might expect, the younger you are, the likelier you are to support gay marriage (18-29s are 43 yes, 52 no, while 60+ are 55 yes, 38 no), but there's also a big disparity between the two congressional districts in the state (the more cosmopolitan 1st is 45 yes, 50 no, while the backwoodsy 2nd is 51 yes, 42 no).
As a bonus, they also threw in the first look anyone has taken at the Maine governor's race for 2010, a race that has been particularly slow to take shape and where nobody terribly well-known is running. The results aren't what you would call conclusive, with 'undecided' winning every race, but show the Dems with a decent margin in every permutation, except for a Steve Rowe/Les Otten matchup.
http://www.swingstateproject.com/diary/5605/megov-still-mostly-a-question-mark