"do the Forums Ninja's get paid??  If so that's cool, if not they're nuts."

They're nuts.

As others have pointed out, there's plenty of room in the Gears storyline for additional material; heck, with that closing cinematic (spoiling no spoilers) they've given themselves plenty of room to flesh out their universe.  I'd be surprised if we didn't see something else follow on from the game.  Maybe (probably) not to the same extent as Halo but something anyway.

As to community feedback, forums have a, er, "checkered" potential.  Since the participants are self-selected, and they're bound to be vocal (if they're quiet, or just content instead of overjoyed/enraged, they won't post!), you have to be really careful that forum feedback isn't reflecting the opinions of a vocal minority.  It's best if you can compare the forum stuff with observations of actual play.

As to community development, well, all I can say is that it's good business as well as rewarding... if you can allocate the resources necessary to do it well, and that (IMO) isn't as easy as some seem to think.

 -- Steve finally finished off RAAM last night on Casual, and enjoyed the heck out of Gears' campaign.