It's quite boring if I'm totally honest. I feel the render should jump out at me but the lack of depth stops that from happening. Also you should position your text near to the render. (Perhaps under his left arm). It seems quite plain and hasn't really got very much going on. I think you should have a look at some tutorials and check out my Graphics Compilation thread (Link in my signature). After reading tutorials, download some nice brushes, stocks, renders, fonts, c4d's and anything else that will help you to create a good signature.
(There are plenty of packs on this forum which will supply you with just about all you will need).
Here: http://www.supportforums.net/showthread.php?tid=11202
(There are plenty of packs on this forum which will supply you with just about all you will need).
Here: http://www.supportforums.net/showthread.php?tid=11202