I'd say Bogut has done okay so far and would certainly be a valuable piece for many teams, but for the moment I'd slot him in just below an all-star type player.
To those calling him a bust, I reckon it is pretty unfair to label the player a bust. Milwaukee clearly made a mistake not taking CP3 or D-Will, but you can't blame Bogut for where he was taken, and shouldn't judge his career by where he was picked.
I think with the right guys helping him to develop his skills and a good team around him he could get to a couple of all-star games and get a lot more notice.
Perfect example that I see every few days is Kendrick Perkins for Boston. KP was VERY raw when he came into the league, but give him two years working with KG and Clifford Ray (big man coach, also worked with Dwight Howard and Al Jefferson) and OMG has he improved.
Not only does he form half of the best interior defensive combo in the league, this year I have watched a slow, plodding big man pulling moves straight out of the KG and Robert Parish play books.
Now KP is not more athletic than Bogut and is certainly shorter (wingspan not sure) and less explosive but he has caught and surpassed Bogut's skill level in the past two years. If I were Bogut, I would be looking for reasons why that has happened. He can definitely be more successful than he is, he just has to get the right coaching and find the right situation.