Some thoughts off the top of my head:
When someone says 'Nike' I think of the swoosh and the ads first, the product second. The reverse is true for Oakley. Why? I don't know.
I hate people trying to sell me stuff, so that's a point in Oakley's favor, since they don't have obtrusive ads. For those ads I do see, I thought the ads that featured the product prominently were nicer than those that feature athletes.
The Time Tank, Crosshair, GMT and some of the other new stuff oozes sex, money and power. Are skater kids and other street athletes the best ones to use to sell that stuff? (I know they're amazing at what they do, but still) That said, Oakley does a good job of marketing to different niches and keeping it separate. The golfers don't impinge on the street sports who don't impinge on the motor sports etc.