In general, the sleeper House seats are in the suburbs of the Northeast and Midwest where the incumbent doesn't know that he or she is in trouble and won't campaign much. Most of these incumbents do have large war chests, which they are already spending on something - though I have no idea really what.
In the NY portion of the NYC metro area, you're not talking about NY-01 (Bishop), NY-13 (McMahon) or NY-19 (Hall) - all of whose incumbents should know their races will likely be close and run for their lives. You're talking about the next tier of candidates - NY-02 (Israel), NY-04 (McCarthy) and NY-18 (Lowey) - all of whom are real longshots to lose, but might not sense that they may be in trouble. The good news for Israel and Lowey is that their potential Republican opponents are underwhelming and underfunded.
In Connecticut, CT-04 (Himes) and CT-05 (Murphy) should be somewhat competitive - and the incumbents probably already know it. CT-02 (Courtney) is probably the only sleeper CT district that I could possibly see flip, depending on who ends up winning the Republican nomination. It won't be Rob Simmons, who would have given Courtney a real run for his money in Simmons' old district. Calling CT-02 a sleeper may be a bit of a stretch given that Courtney barely beat Simmons in 2006, though.
In Massachusetts, the only seat on anyone's radar is the open MA-10. It's really hard to see any other MA seat flipping, but MA-05 (Tsongas) or MA-06 (Tierney) would probably be the next most likely. If you assume Brown outperformed in MA-03 because it included his hometown, he performed next best in MA-02, MA-05 and MA-06. Republicans have always hoped Tsongas was vulnerable, though it has never happened. In MA-06, with his own money included, Hudak almost raised as much money as Tierney in the first quarter, but Tierney has a huge warchest. None of the MA-02 candidates seems impressive or capable of fundraising or winning.
MA-06, and maybe MA-02. Tierney is a much stronger incumbent than Tsongas, and Meas is a better candidate than Hudak. Neal would have been gone with a decent GOP candidate. Major recruiting failure for the GOP.
ME-01 is a weak and unpopular Democrat v. a weak Republican. In a low-info race where Pingree is on auto-pilot, she could get into real trouble. If she engages though, Scontras is probably way far to the right. Which to be fair, is less bad than being a lunatic and having by-weekly staff turnover, which is Hudak's problem.
