Here is a good blog about his ethnicity, and some other Tiger tid bits.
One of my teachers showed us the episode of Oprah in which he dropped the "cablinasian" bomb in response to the attention he was getting as a Black golfer. Even as a child, I found it odd that it wasn't enough for him to say "My dad's Black, mom's Asian. I'm Black and Asian." Tiger had to let us know he had White in him too.
I allow Tiger the space to define himself as a multiracial man as opposed to a Black one. It's his right (though I believe it is more of a function of his desire to distance himself from Blackness than it is to be accurate in describing his heritage.) As a result, he's never been a "brother" in my mind. I still appreciate that he's a person of color who broke a lot of racial barriers in golf, though I winced every time he was subject to blatant racism (the Fuzzy Zoeller comment, the reporter who said he should be lynched) and did that turn the other cheek tap dance. Perhaps 'cause he has White in him, he didn't take it personally.
I've always viewed him as a nerdy asian golfer with dark skin. He certainly is a person of color, but he doesn't seem to want to attach himself too tightly to being black.