I've enjoyed Lost this season, though I know it's gotten a mixed reaction. Veronica Mars started out as VM Lite, but there have been some great episodes. The most recent one was really good. Don't know if you know, but it's finally been picked up for the rest of the season. They wanted an additional nine episodes, but only got seven more. I don't mind being two shy, but I hope it isn't a sign that a fourth season is off the table.
I would sincerely doubt it gets to a 4th season, regardless. The ratings have never been stellar, and only a small-but-loyal fanbase has kept it afloat for a third season. Plus, it doesn't seem to have the same spark that it did when Veronica was at Neptune High. Same with Smallville...this is a relatively weak season, if you ask me. They never should have killed off Jonathan Kent.