There are significant changes with all three selected national bookies after the first test session.
Hamilton continues to loose ground from his initial favorite position to Alonso and Schumacher who both managed to improve to the level where Hamilton started. Alonso must be profiting from the good testing times the Ferrari could demonstrate, while Schumacher managed to kill off most concerns about his injury and immediate capability to go fast again.
The tier two group sees significant change, only Vettel remains pretty much where he was with a slight improvement. This corresponds with what we have seen from the other three top teams before they tested. Rosberg improves significantly although he was twice slower than Schumacher. People must have seen him much worse than he actually is. Rosberg takes a lot of support from Button who plunges deep as the world seems to loose confidence in the McLaren. It seems pretty clear that most people do not see him as a WDC by merit, or he would have started with much lower odds. Personally I don't see the bad perception of the McLaren justified. They did successful flow-viz tests on their mega diffusor and set their times with significant fuel loads. Massa did well in the Ferrari and stopped any concern about his injury. I see Massa lead the tier two section in the future if Vettel joins tier one. That will most likely happen if the Red Bull is only half as good as the last years car. Webber improves and catches up with Button and Rosberg and has now fully arrived in tier two.