The colors are nice, the effects are well done (but there could be a bit more done). I agree with Monroe about the background blur. I would suggest unblurring the areas closer to your render to create some actual depth. I the case that you used a stock in the BG, you want to choose what part of the stock is closed to the front of the sig. This of your sig as a window. Whats at the front of that window is very clear, whats father back in that room is blurrier. So remember that when using Background stocks... this will really help you create some depth withing your sigs. I noticed Monroe mention your lighting, personally i dont even really see much lighting going on here... just a brighter part of your bg stock. What i would suggest is lowering the brightness and contrast on that bright part of your bg, and the creating a new lighting source using a 100px soft brush and other lighting techniques.

Keep up the good work... i love the text you have.