In 2010, you could easily make a case for Messi's teammates Xavi Hernandez and Andrés Iniesta, as well as Inter's Wesley Sneijder.
This year, however, it is impossible to look past Lionel Messi. While his teammates Xavi and Iniesta were undoubtedly superb, Messi was clearly a level above them. Real Madrid's Cristiano Ronaldo had a season for the ages (not that far behind Messi, statistically speaking), but his club's shortcomings in La Liga and the Champions League mean that he won't repeat his 2008 triumph, even if he is the favorite to get second place.
It's just difficult to see who can challenge Messi for the award. Unless something very weird and unexpected happens, it will be Leo Messi, for the third year running, to lift the Ballon d'Or, thus equaling the record set by Zidane, Ronaldo, Platini and van Basten. Considering that he's only 24, it would be a huge surprise if Messi didn't end up being the sole holder of this record.