Eh, I don't like the designs. I've never been big on the whole Twilight Express style of CGI figures who look as much like real people as possible; I find it kind of creepy and off-putting. If you're going to make your CG characters look like real life people, then I say go the whole 9 yards and make it live-action.
Plus, based on the ads I've seen for Mars Needs Moms, it looks like it deviates too much from Berke Breathed's book (the fat guy stationed on Mars and the alien chick weren't in the book) and it just doesn't look like anything I'd go out of my way to watch.
I'll probably wait for this one to come to cable/satellite.