Also, I am not sure that all of the WotC Modern books have been of that high of quality, as opposed to ther other lines. d20 Past was pretty bad, for example, and Green Ronin's Ultramodern Firearms was better than WotC's gun book, IIRC.
Obviously, I say this as a writer of 3rd-party Modern stuff, but if WotC didn't put out anymore I would be okay. d20 Spectaculars is unnecessary when M&M and Blood and Vigilance and others are already out there... though a d20 Marvel game (and lots of stats) would be cool.