Seattle has Felix and Pineda and as of late, Bedard. At best, Maholm is their 4, although Vargas is in there.
KC - not much going on there. A bunch of 3s and 4s. Hochaver, Davies, etc. Maholm fits in, but is not substantially better.
Washington - Obviously the problem there is Strasburg being hurt, but with Strasburg and Jordan Zimmerman, Maholm is in the mix with Livan, Lannan and Marquis for a rotation spot.
Arizona I have no idea. Ian Kennedy and Daniel Hudson are the only two I can think of. Hudson has more upside than Kennedy or Maholm.
Mets - that's not a major league team. Santana, if he ever gets healthy. Pelfrey. Dickey. Who else do they even throw?
Blue Jays? Morrow and Romero are substantially better than Maholm and Drabek is just as good and probably five years younger.
I would not mind Maholm being traded from Pittsburgh, but for once the Bucs are actually decent, so that's not really an excuse any more. Every pitcher loses games to the pen. There's no telling how many the combination of Bobby Cox and the Braves pen cost Maddux and Glavine, but they were good enough to take care of business on their own most of the time, so you didn't hear about it a lot. Is there a stat anywhere that says how many games the bullpen blew for starters? Not that wins are the defining stat, but that seems to be a reason people give for Maholm's struggles.