You left out the Neimoidian Warrior, Chewie. But yes, the Seperatists aren't getting that much play. The Tank Droid and the Droid Gunship would be very welcome in my collection.
Thing is, the Seperatists aren't the main villains of the movie. As such, I can see why they would get marginalized. The Empire and the Sith are the main enemies of REVENGE OF THE SITH. The Seperatists are merely pawns, just as they have been all along. Would it be nice to get some of the Seperatist leadership? Sure. I see them being a good source for Collection 2 in late '05 and early '06. But how many Nute Gunray's do we really need?