Despite of kicking Holland out of Euro 2008, he's generally admired I think, for qualifying 4 different national teams to big tournaments and taking them far into the tournament every time (3 semi-finals, only Australia were unfortunate against Italy). Many people consider him the best Dutch coach at this moment, and I tend to agree. But his reputation took somewhat of a dent 2 years ago after he was suspected of tax evasion.
His amount of lucky escapes also earned him the nickname "Guus Geluk", which happens to be the Dutch name for this Disney character:
(you know, the one whose luck defies the laws of probability)
I would have liked to see him return as manager for Holland, but alas, Hiddink's not interested.