the williams looked like a race winner last year too. You don't know anything until melbourne and the 2nd GP. As I can remember last years form book from winter testing was that Kimi looked the best, with Macca in slight trouble, and a resurgant Williams team. A BMW were gonna win a race on pace as well.
What really happened was Kimi was pants, Mclaren got it sorted, Williams were average at best, and BMW never had enough pace to win a race without huge luck. Also no one else could predict from testing the pace of the Renault in Alonso's hands at times after their winter testing program.
McLaren do seem to trying many odd things that's for sure, something isn't right going on. Or maybe they want to keep some secret wing design secret? HHmm.... doubt that tho with such limited testing
What I do know is that if Toyota will quit if they don't win a race, I suspect they will 'somehow' grab a race victory.
the trouble with testing is you never know if the cars legal or not, eg ferrari have been using an illegal exhaust this year as they didnt have the 2009 regs one available. more seriously in the past teams have run under weight to make the car faster and keep sponsors happy and unlike ferrari's exhaust they don't bother to tell anyone. unless anyone does a long run you cant be 100 % on how heavy is their fuel load either and some teams in the past have run their cars wth full fuel whilst pretending it was light fueled just to hide an advantage they had.
given the new regs and how confident some teams are in the computers doing fluid dynamic calcs i won't be surprised to see a few new wings appearing at the last possible moment
Don't know if it has been suggested already but instead of quessing who'll win the championship how about quessing if the number of broken front wings be over or under 100 when the season ends?