The best blog I’ve come across for following news of the Mars Exploration Rovers is Martian Soil. I’ve got it bookmarked now, for sure.
One link I found through there are 3-D stereoscopic images from the rover.
UPDATE: Another great weblog for following MER stuff is 2020 Hindsight, which links to an account by Dan Maas of how he created that great animation of the MER launch, travel, and landing.
UPDATE2: Asa Dotzler is blogging his notes from the MER press briefings. They’re really great.