He's only 24, no doubt he can change it, just look at Verdasco and Soderling...
True - he seems to have been around forever.
Verdasco is a lot quicker around court though, and was a relatively late developer - he didn't crack the top 20 till 2008 (aged 25). Not sure that's too useful a comparison.
Sod is obviously much more similar in style though, and he had his RG breakthrough a little before his 25th birthday. Berdy is 25 later this year, so all is possible .......... but can he find his Magnus? :-)
Interesting if he could, because there's potential for him to pick up points absolutely everywhere. Grass, indoors, fast hard (Tokyo last year), slow hard (Miami), clay (Monte Carlo 07 semis). With a brain, he'd be a cast iron certainty for the top8 again - the top5 are a class above, but he could easily fit into the Davy/Sod/Verdasco/Gonzo/Roddick/Tsonga tier just below.