I think he's enjoying his tennis as much as ever, and as long as he continues to enjoy it - and doesn't see his standard slipping - then he'll keep going.
I, for one, don't think his standard has slipped too much.
Perhaps he's not quite the player he was three years ago, but he's a better player than he was last year, that's for sure.
That said, three months into the season I'm not so sure that Federer's advance is quite as strong as I thought it was.
He's starting to find that the top standard he's capable of reaching today might not cut it against Novak Djokovic and Rafael Nadal.
One thing's for certain - he desperately needs to win in Miami.
Whatever happens this year, I think that the 2012 Olympic Games (to be held at Wimbledon) will be absolutely huge for Federer. It will be a watershed moment for him.
Maybe there's one more Grand Slam in him, possibly two, but at the moment the pecking order is Nadal on clay and Djokovic on hard courts, leaving Wimbledon and the Olympics as Federer's best chance of claiming one more big win.
The Olympics is the one accolade missing from the great man's trophy cabinet and if he wins Olympic gold, I really think that might be it for him.
The only other thing that would keep Roger playing is he seems a man for history: he won't be too happy leaving while Nadal relentlessly continues to pick up Grand Slams.
Who knows what's going to happen in the future; in 10 years' time we might have another Federer.
However, is anyone really likely to win as many Slams as that in the next 10 years? It's very unlikely.
The only man who could do it is Nadal, so if he can keep nagging away at the Spaniard - rather than the other way around - then that might just keep him in the game a little longer.
Ultimately, Djokovic could give Federer's record a helping hand by challenging Nadal consistently at the top of the game, especially on the hard courts.
If I was Roger Federer, I would be sending Djokovic 'play well' cards!
As I said last week, if Novak can keep playing at the level he's shown us recently, he can really challenge Rafa's domination at the top of the men's game.
I still see Nadal winning the French Open this year, and either he or Federer will probably win Wimbledon, but I'd pick Djokovic for US Open glory, hands down.
At the moment, provided Nadal and Djokovic stay fit, I certainly can't see Federer getting back up to world number one.
- Roger Federer
- Novak Djokovic
- Rafael Nadal