It's the smart move. Laurence Simon at Amish Tech Support lays out the reasons why he'd be an idiot to move to broadcast, which covets him:
Jimmy Kimmel went from Comedy Central's Man Show to that piece of shit he's got on Disney's ABC that stinks up the airwaves after Koppel.In the same post Laurence also notes that Colin Quinn may have found his niche on Politically Incorrect. Haven't seen it, but the commercials do make it look interesting.
Bill Maher got away with a lot of lefty gaffes when he was on HBO, but Disney wiped him out in spades when he screwed up on Disney's ABC. He's back on HBO, I believe.
Dennis Miller tried to go from an HBO series to Monday Night Football on Disney's ABC, then got bumped for some burned-out fat old guy
Wait... I see a pattern here... hold on... wait... wait for it...
Nope. Lost it. Must have just had Post Disney Traumatic Disorder there or something. Sorry.
Update: The spelling of Mr. Stewart's first name corrected at Emily's behest.