To a degree, mileage has a bearing on the wear on the drivetrain and brakes. Now, if it's been well cared for, it may not be such a big deal, but I'd take a look at the cassette and crankset and check for wear. Do the teeth appear to be worn?

There's a picture of a worn sprocket and a comparison with a new one here:
http://sheldonbrown.com/chains.html#wear

Scroll down a little. It's the one without the chain on it