[Ainaserkewen]

Legolas is an interesting character...
A supporting character yes, but nessesary.
For one, Tolkien hasn't spent much time describing his character, so he comes off as very mysterious. We know he is the prince of Mirkwood, but the Mirkwood elves are strange and unknown, I am trying to descover some of their more detailed history in the Silmarillion and the Unfinished tales, looking for clues and information on the king and his people. So since there lacks information on them, we don't know how old Legolas is, who his mother is, whether or not he has siblings...etc.
So we don't really know this character, except that he's an elf, and a cool one at that. He's kind of on the same level as the dwarves, you don't know much about them, but they're there and very cool.
Picking on the movies a little, I think that even though they did a good job in keeping Legolas mysterious, they did make him of a showoff. The archery for one, and the mounting on the horse and the slidding down stone steps. You all know what I'm talking about.
My opinions on Orlando Bloom himself are that he's an attractive member of the cast and because of all his cool stunts he brings a audience of Nazgirls to the theaters, a marketing scheme of the producers no doubt. At least he, in my opinion, is a really good actor, not just a pretty face.