For your first piece of art using your tablet and painting in Photoshop, this is very impressive! (not to mention ambitious!). I must confess that I too am a fan of the blizzard style of art. I have a few of their art books for some of their games. Anyhow, your use of color here is very well executed. I was particularly impressed with your attention to detail in things like how the skin has shadow show from where the clothing is against it. The saturation of colors is great too. I'd suggest adding some patterns on the clothing to break up the flatter areas a bit, but overall you should be very proud of this :)