There is little usefull knowledge to be taken from any times untill Qualifying 1 in Melbourne.
I have to disagree with that. In general the fastest guys in testing (once the new cars are released), are generally the fastest guys in qualifying/racing, when the season begins.
In the last few years, McLaren and Ferrari have dominated the pre-season testing and have carried that form into the race season.
In 1993, Williams had the best car by miles. In 1994, in pre-season testing, Bennetton were generally the fastest in pre-season testing. Everybody thought that Williams were sand-bagging (why anyone would do this is beyond me) and that there was no way anybody could've caught Williams so quickly. When the season opened up Schumacher/Bennetton won 6 of the first 7 GPs of that year and the only GP he lost was due to being stuck in 5th gear for most of the race.
I cant actually remember the last time a team were great in pre-season testing and then failed to carry that form into the racing season. It hardly ever happens.
In summary, pre-season (Jan/Feb) testing provides a very good indication of which cars/drivers will be the fastest when the season begins. The cars that dominate pre-season testing will almost certainly be the cars to beat in the first few GPs of the 2009 season.
Obviously, the testing times being posted right now are of no meaning to us as the 2009 cars are not being used, though to the teams, the current testing times are very important.