Button joins Lewis Hamilton in an all-English line-up that will have those watching F1 salivating.
Some will be attracted by two such appealing figures in the same team – not to mention the glamour that will be provided by their respective girlfriends.
Others will be fascinated to see how the two drivers match up on the track.
And that is where the risks for the McLaren new boy are immense, even though Button has seven years’ more experience than his new partner.
Hamilton is considered by many observers to be the fastest driver in F1. Button may be the reigning world champion, but he has not yet proved to be quite in the same league as Hamilton, or the new Ferrari driver Fernando Alonso.
Meanwhile, Sebastian Vettel was shocked by title rival Button’s move to McLaren, and expects Mercedes GP to be a strong contender in 2010.
The German, who finished second in this year’s world championship, said: “I think it was a surprise to everyone,” Vettel said. “Brawn GP, now Mercedes GP, was very strong this year. Lewis knows the team very well, already for a couple of years now, Jenson is the new one coming in, so we will see.”