SurveyUSA (10/4-5, likely voters, 10/26-29/2007 in parens):
Jeanne Shaheen (D): 48 (53)
John Sununu (R-inc): 40 (42)
Ken Blevens (L): 7 (-)
(MoE: ± 3.9%)
Keep in mind those trend lines are from nearly a year ago, which just underscores how thoroughly strong Shaheen has been in this race. In fact, of all the many, many polls of this race since Shaheen's entry, we've only seen two that have showed Sununu ahead -- and those polls were by the sometimes-wobbly Rasmussen, and the often-funky ARG.
Bonus finding: Obama leads McCain by 53-40 in the same poll.