Berdych is 21, is he not?
It doesn't matter which one of Nole or Andy gets there first - they are both going there eventually and are probably going to stay there for a while. I think Andy has the better all round game and has better results against top players, although I think Nole is a more consistant player who won't have the fluctuations in form or suffer as many bad defeats. They are both incredibly talented and are legitimate top ten players.
It's hilarious people trying to build some bitter rivalry between them considering how uninterested they are in that. They are friends, they say nothing but good things about each other, they want each other to win and do well and then you come on here and you get people trying to build it as some be all, end all, fight to the death, I hate you and your entire blood-line, grrr rivalry.