Final Cut and Premiere can and often are used for broadcast-quality work. In fact, were either of them to get a decent back end for direct-to-air video servers, I think they'd kill Avid. The Airspeed system is nice and everything, but the actual editing in Avid is archaic compared to the ease of FC or Premiere. The only editing advantage Avid has over those two is that its color corrector is worlds better, and some of its more jazzy effects are. . well. . more jazzy
Nothing that After Effects or Motion can't wipe the floor with, though.
Basically, if you don't need a tapeless broadcast environment (i.e. your video gets uploaded from the edit bay to the on-air server, and is played without the need of a tape) then Avid is not, in my opinion, the editor for you.