From eurosport.com :

The penultimate pre-season Formula One test came to its conclusion on Friday with Honda, Renault and McLaren proving without doubt that they are the teams in form going to Bahrain. Honda's Jenson Button ended the four-day test on top, marginally ahead of both Renault's with Juan Pablo Montoya fifth. The quintet were separated by just half a second as the three teams finally began to unlock the performance of their respective cars. Button roared to the fastest time of 1:13.935 on Thursday, beating Renault's Giancarlo Fisichella into second by just 0.036 seconds with Fernando Alonso just 0.006 secs further adrift in third. McLaren enjoyed a more productive test with Juan Pablo Montoya capping their week with a mammoth total of 131 laps, clocking the fifth fastest time of 1:45.588 to be just over half a second shy of the leading Hondas and Renaults. "There have been a few problems with the car, but generally it has been a productive week," said the Colombian. "It has also been quite cold here in Barcelona and with everyone testing different things, it is difficult to compare the performances of the teams."

I actually didn't expect Honda to already be with the top teams, but a three-way battle for the championship wouldn't be too bad, would it ?