Or a combination of all of them. Chuck's a cult show by it's nature. Like Buffy or Supernatural. Go to any of the NBC boards Chuck fans outnumber Heroes fans or Office fans 3 to 1. That's the only thing keeping it from getting Knight Rider like numbers. A new night would be wonderful for both shows. Because a cult show just can't stand up against juggernauts like CBS's comedy shows and the rest.
Personally, I think they need to move Chuck to USA, as it's a niche show and would fit in well there back to back with Burn Notice.