– The ratings for the return of “Prison Break” were poor, and TV By The Numbers says that it’s bad news for “Dollhouse.”

– One of my favorite shows, “The Unit,” is on the bubble, but the good news is that producer Shawn Ryan (“The Shield”) has been invited by CBS to present ideas for a fifth season.

– The NY Post says that Mary Louise Parker is thinking about leaving “Weeds” after next season.

– FOX’s “Sit Down, Shut Up” didn’t do all that well (ratings-wise) in its debut on Sunday, considering it was sandwich between stalwarts “The Simpsons” and “Family Guy.” I’m a fan of both of those shows, but I couldn’t make it through a full episode of “Sit Down, Shut Up.”

TiVo is continuing to move into Nielsen’s territory. They’ve been offering national ratings since 2007, but now plan to provide market-by-market ratings as well. It makes sense — the TiVo is essentially a computer that can track what a household watches (if they choose to opt-in).

– Variety compares “Heroes” to “Lost” in that both programs started off really strong before faltering a bit. The question is — will “Heroes” find its way like “Lost” did? (Methinks maybe an end date two or three seasons down the line would do the trick.)