Zach Braff and several others on Scrubs have said this was their last season no matter what from the beginning when ABC took it over so there really wasn't ever a chance for it to get picked up again. Too bad because this season was MUCH better than the last couple.
Use Hulu as much as you can though - ABC has a REALLY annoying commercial model that requires you to leave full screen mode and click to advance - really annoying when I'm watching from bed!