The 2009 Formula 1 World Championship campaign will roar into life after a nigh-on five-month winter break this weekend, with the Australian Grand Prix in Melbourne promising to be one of the most open, unpredictable and exciting races in years.

With the top flight's substantial raft of regulation changes - the introduction of KERS (Kinetic Energy Recovery Systems) technology, the much-anticipated return of slick tyres and dramatically different front and rear wings - the form book has been thrown out of the window. The curtain-raising event on the 2009 calendar could, quite literally, be anyone's race.

On pre-season testing form, however, it is unlikely to be Lewis Hamilton's, with the man who triumphed both Down Under and in the title chase last year grappling with what appears to be an uncompetitive McLaren-Mercedes, as his Woking-based outfit struggles to get a proper hold on its new aerodynamic package. That situation is likely to similarly account for team-mate Heikki Kovalainen's chances - with points the suggested target for both drivers - but if McLaren can't win in Oz, who can?

Well, pretty much anyone, to be honest. Ferrari have appeared to be strong in testing, with the F60 fast if not always reliable, and the Scuderia finally seems to have gotten on top of the KERS issues that so badly plagued the new car's birth. Felipe Massa is determined to make this year his own after so agonisingly missing out on the laurels at the last gasp in front of his adoring home supporters at Interlagos back in November, and former world champion Kimi Raikkonen will simply be keen to show the world that he's still got it at all, after a desultory 2008 when the Finn all-too frequently gave off the impression that he was there in body but not in mind.

BMW-Sauber has been solid throughout the winter, and Robert Kubica and Nick Heidfeld - quick and safe hands both - can be expected to pick up the pieces if the established 'grandees' stumble. The Munich and Hinwil-based concern has made it clear that championship glory this year is very much the goal - but it will need to extract a little more performance out of its F1.09 if is to do so entirely on merit.

Fernando Alonso and Renault can also be expected to be up there in Melbourne - with the Spaniard desperate to reclaim title-challenging form off the back of a superb end to 2008 - whilst Toyota could yet prove to be a dark horse Down Under, with a car that looks fast, consistent and reliable...and one that former Monaco Grand Prix winner Jarno Trulli has described as the best he has ever been given by the big-budget Japanese manufacturer. Diffuser permitting, of course.

That same point applies to the Williams and pace-setting Brawn GP challengers, with the latter widely tipped as pre-race favourite - an astonishing turn of events given that barely a month ago there were serious doubts as to whether the ex-Honda outfit would be on the starting grid at all. In the hands of both Jenson Button and Rubens Barrichello, the new BGP 001 has stunned seasoned observers by tearing up the test tracks in recent weeks - and Australia will be the true acid test as to whether it has all been one big sponsorship-attracting bluff...or if the pace is as real as it seems.

Further down the grid, Force India can expect to gain some places with its new McLaren-Mercedes technical and engine-supply tie-up - though how many places that will be is unclear - whilst Scuderia Toro Rosso will likely merely be hoping its new STR3 goes the distance in Albert Park, having largely failed to do so in testing.

There could be happier news, though, for 'parent' concern Red Bull Racing. With the home hero and F1's latest superstar on the driving strength in the form of Mark Webber and Sebastian Vettel respectively, and a nifty piece of design work from Adrian Newey in the shape of the Renault-powered RB5, many reckon RBR could be the darkest horses of all. Roll on Sunday!'s Tip for the Top: Sebastian Vettel's One to Watch: Nico Rosberg