I think McLaren will still have the prettiest car, or at least the prettiest nose.
The second test should be much more interesting than the first. Reliability issues should be mostly ironed out, Mercedes will debut their 2012 contender, and the teams will be able to apply lessons learned during the first test to improve their cars and driving styles.
General rumour-mongering indicates that Red Bull and McLaren have the best-behaved cars, while Ferrari suffers from too much understeer, and Lotus is generally solid albeit with poor stability under braking.