I must admit I know little about Kwanzaa, but I'm trying to learn. I have no opinion about it yet. I can say that if I ever run into La Shawn Barber at this time of year, I won't say Happy Kwanzaa to her.
UPDATE: Here are two different views of Kwanzaa: The first, by blogger Cobb, is supportive, and the second, by Mary Katherine Ham on Hugh Hewitt's blog, is decidedly less so. Both views are well-reasoned and interesting.
My own bias is that I'd like to see less emphasis on differences and more on what we all have in common. I don't like racialism and its emphasis on racial identity and separateness. But if black Americans want to establish and celebrate a holiday that emphasizes sound principles, I will live and let live.