Exile of Rochesterturning reports on his conversations with regional Democratic leaders about the Nachbar candidacy. He believes that Louise Slaughter will not officially endorse Nachbar for the 2008 race, and that most of the town and county Democratic committees will publicly support Massa. My sources aren't as numerous as Exile's, but a source that I trust has also reported that Slaughter will not endorse Nachbar this time around.
Exile mentions that he started getting DCCC press releases around the time of Nachbar's announcement, and speculates whether Nachbar is their candidate, since he's using a PR firm with ties to Rahm Emmanuel, the DCCC chair. I don't know about the PR firm, but I've also been receiving those press releases, which are formulaic, low-quality efforts.