Not only is a new Heroes on, but the latest episode of Dexter is generally available for viewing by those of us without Showtime.
And speaking of Dexter, I read the first two novels over the weekend. There were definitely quite a few changes... but I think the series did a great job of turning the first book into an entire season's worth of episodes, and fleshing out a number of the minor characters.
But one thing from the novels that didn't seem to make it into the series was Dexter's observation that Vince Masuoka is also pretending to be human (yet he doesn't trigger the same suspicion from Doakes). But the second novel (which is apparently not the basis for the second season) did explain a plotline from the first season which seems to have simply been dropped, which was the shooting Doakes was involved in.