Seems to be a complex personality. Can be a bogan and, as Jono said, plays the game very seriously (although who are we to judge if that constitutes being too serious?) but I distinctly remember him being excellent value when mic'ed up in the 20/20 against NZ in Perth. is probably a fair bit more analytical and introspective than people give him credit for which is borne out by the fact that he was able to change his game fundamentally (from 5-over slogger to Test batsman) to make it as an international cricketer which very few people can pull off.
I think personality-wise, he suffers from poor perception because he has the unfortunate combination of being really emotional and brutally honest (surely, holding the view that players shouldn't be nice out on the field is the height of emotionalism? It's not based on reason, that's for sure). Sometimes he's really honest with himself; when asked what was different when he scored 143 in that WC game against Pakistan, said something along the lines of "I finally grew a brain." and many times he's probably a bit too brutally honest with others. I think it's clear he's from the AB school of 'tired of being a nice guy and losing, would rather be a prick and win' because, years ago when he was playing against a mate of mine in State U/19 champs and belted the SA attack for a (very) rapid double ton, was known as a really great bloke. Should have heard what people were saying about Ponting back then.....! I honestly don't think he's any more arrogant than other international cricketers, reckon he's just less capable (or inclined) to hide it.
Playing-wise, as someone already mentioned, choosing the infinitely tougher path of playing for Australia, when no-one thought he would, was a ballsy move. He's managed to overcome technical limitations to be a a decent Test bat. Combine that with his fielding and handy bowling and you have one heck of a valuable player.