I've struggled to stay interested in Smallville for the last half of this season. The show's gone completely over the top with various Kryptonians possessing various Luthors and the desire to drag out and beat to awful, bloody death the Clark-Lana relationship angst. Honestly, the only reasons I've kept watching have been Chloe and Lois. The final nail in the coffin for me though is that ABC is moving Grey's Anatomy to Thursday nights.
Grey's is going up against CSI, in the hour following Smallville, but I'm never home on Thursdays and my DirecTV prevents my being able to set up the VCR to change channels in between shows. That means that I either get TiVo or I make a choice about what channel to record on Thursdays. With as good as Grey's Anatomy is, there's no contest. I'll be recording ABC. (My youngest brother is a big fan of Smallville, so I'm sure he'll keep me in the loop if the show starts to get good enough that I need to borrow someone else's VCR.)
Another change in my TV viewing this fall is that Surface has been cancelled by NBC. It wasn't a great show, but of the three new "alien" shows this season (Threshold and Invasion being the other two), it was the only one to keep my interest. It got pretty hokey by the end of the season though and I was pretty much only watching it for Lake Bell.
Other shows that I currently watch -- Gilmore Girls, The Unit, and Lost -- all seem to be staying where they are. The only new show (so far) that has my interest is J.J. Abrams's Six Degrees about "a group of strangers brought together in New York City by a series of mysterious coincidences." Frankly, I'm not as excited about that as I was by the concepts of Alias and Lost, but I'm always willing to give J.J. Abrams a shot.