I think it looks awesome and excellent! Makes me wish it were truly a movie because just from this poster alone it would rock. Heck would you mind if I made this my background? Won't screenshot and say its mine, just a cool background to be like 'MAN must level Forsaken and take back Lordaeron for mah Queen!'.
I think it looks good. My main suggestion would be to adjust the angle of Sylvannas, as it's quite difficult (for me at least) to tell who that is. The quiver and the cloak gives her a hunched look, and I thought it was male troll!
I like the rain effect and the overall mood of the image!