As far as defeating McCarthy is concerned, it is doable, if there is low turnout on the Dem side. While the district has seen some demographic changes since the 1990s, let alone the 80s (especially in Valley Stream and Elmont in the SW part of the district, which are now essentially an extension of SE Queens demographically), the biggest voting bloc are still white "Catholics", who can swing toward the GOP depending on how the political winds blow. There is also a growing Asian (especially Korean) christian population in the NW part of the district, but the GOP has done little to make inroads among this affluent group (who also have high rates of voter turnout).
Irrespective of whether we can retake the NY-04 in 2010, we need to take back the state senate (and, hopefully, the govermorship as well) so that the black-majority NY-06 is extended from Queens into black areas in Nassau (at least to take in black parts of Hempstead village) and the NY-04 becomes a more Republican district.
Maybe we should run a Korean-American from the private sector against McCarthy ?