I don't think enough is said about how essential Trevor Ariza has been to the Lakers's recent success. Yes, Kobe Bryant and Pau Gasol are the backbone of the team, and the guys who are going to shoulder the majority of the burden of scoring and facilitating the offense. But they alone are not sufficient to make the Lakers a championship team. They also need to be surrounded by players who can take advantage of the mismatches that they create .
As the post I've linked to above shows, Ariza is that guy. When Kobe and Pau draw in double teams, Ariza is there to take the 3-point shot, slash to the basket, get garbage rebounds, or whatever. He literally does anything you need him to do. He defines utility player. He plays tenacious defense, gets sneaky steals, and comes up with huge blocks. His most important skill, though, is just showing up when it counts the most. While I don't have a scientific survey of the Lakers's games this season, I can remember any number of times when the Lakers were struggling, and Ariza would come up with a huge play to ignite the offense. Who can forget the huge steal he made at the end of Game 3 (assisted by Lamar, of course)? The dagger threes he has hit all season? His tenacious, fierce, physical defense against Hedo Turkoglu in these finals?
It seems more and more to me that the Lakers weren't missing Bynum so much last year as they were missing Ariza. Admittedly, we probably still would not have won the Finals, as the Celtics were still too physical and hungry. They wanted it, and we shrank before their desire. But their path would have been much less easy with our talented young swingman roaming the parquet floor.