It just goes to show that you can't put a ceiling on a player and some are capable of big improvements later into their career. In James' case I think it was more to do with consistency than ability - he's proved before that he's capable of performing to this level - and he seems to be a lot more calm on the big points (in the past he was always prone to playing very passive when trying to serve things out). Apparently he's now working with his own full-time coach (funded by himself), which I'm sure has helped.
I should also add - this win means James will now qualify for the Australian Open main draw outright.
First time since Henman was playing in 2007 that we'll have two Brits in the main draw of a slam on ranking.
I really hope he can break that 100 barrier - it's only a number at the end of the day but I'm sure it's also a fairly big psychological barrier for these guys - and hopefully go on to rise even higher. There's really not all too much difference in ability between 50 and 150, and James only has to look as far as the likes of Dodig or Estrella to see that there really is no reason why he can't continue to rise.