Hayden is incredibly consistent, he's usually top 4 or 5. He's having a good run this year, but he still hasn't made the jump and really beat Rossi or Caparossi head to head. They were both riding hurt when he was able to stretch his points lead a little. It would be great if he can win it, but it won't convince anyone he's the best rider on the grid. The two Italians have had terrible luck with equipment problems and injuries this year. Nicky would be fighting his teammate for 3rd in points if they had better luck this year.
Having said that, with four races left Rossi could win out and take it from him. Pedrosa seems not of this planet. Who rides with a gaping wound and busting out the stitches in their knee? Holy crap he wants it bad. Nicky is just one DNF or a couple of bad races from losing it to either of those guys. Hayden's a great rider, but he's just not on par with Rossi (aka God) or even Caparossi. He and Pedrosa are pretty evenly matched, but keep it mind it's only Pedrosa's first year on a big bike and he is Oompa Loompa sized. Next year the bikes get smaller and Pedrosa will be hard to catch.