So, todays testing has pretty much told us nothing!
Looking at the times doesn't really say a lot, we have no idea of fuel loads, or how hard drivers were pushing (especially with talks of Alonso slowing on the straights). The mercedes appears to have had a few teething problems, and Ferrari may be having an aero issue with the rare wing that hadn't been thought of over the winter (alternatively - they've found a way to improve it). We can't really compare drivers in the same team, because again we have no idea of fuel loads! The only thing I can think of is that the margin between the drivers wasn't too big, if a team had been 10 seconds clear I'd have been worried!