First off, the good. I really like the subtle use of texture. It is so subtle it could almost be missed, which could be a problem, but in general subtlety is good. You might want to increase the opacity on the texture layers just a very, very little bit, but it is not a big deal. My favorite texture would have to be the one you used on the green parts, btw. In fact, the little green leaf-like parts are very nice in general; they look nicely 3-d.
I also like the three swoosh-like things in the bottom right corner. I don't know why, exactly, but they are cool.
I also like the colors. Though they are not what I would typically think of as colors that go well together, you have managed to make them work excellently. The entire peice looks alove because of it. The darkish-blue purple looks a little out of place, but there is not that much of it anyway, and it is very slight.
But I don't really like the overall shape of the piece; I am not fond of spirals. Also, the ying-yang like spiral at the top is bugging me. Not just because it's a spiral, but also because the colors become muddy there. See, because the colors look are so contrasting, it makes them look alive - like I said in the previous paragraph - but when they get too blended and too close together it does exactly the opposite.
If I were you, I would zoom in to a different part of the piece to not show the ying-yang part, and also to make it look a little less like a spiral. Perhaps do something like show the 'spokes' of the spiral, but not the actualy center, sort of like in this fractal. [link]
Also, I would try to soom in so that I emphasized the green parts as much as possible, because as I said, those are very well done... and I would try to keep the swoosh-things in it as well.
Overall, nicely done.