Love it love it love it. It's a really original style at least compared to the trees I've seen. The foliage Is fantastically random, it's so hard to make random look right. The levels and lighting look great, though I probably wouldn't have used the lighter shade on the bottom part. The only other thing is the bottom part of the trunk looks a bit straight and not as 3D as the rest.
The funny part is it's inspired by a tree I saw in an episode of King of the Hill. There are a few different versions, but once you see it with the rest of the style, it's not going to look too similar.
Actually, even though it says in the description not to use, I'm contemplating letting people use it. I may take a different approach to the style, I may not. But I do have some prototype outlines made up for some... Things (I don't mean anything nasty).