thanks, also i was kind of wondering if you guys know if the official dovahkiin wallpaper was made using a special program, or did the artist just take a long time to make it look so detailed? and is it possible that the dovahkiin wallpaper could ave been rendered in a 3-d program or would that make it too complicated.
My guess is that they used a 3-D Model from the game, and then used Photoshop on top of that. Much like the Fallout 3 Promotional images, http://fc06.deviantart.net/fs35/f/2008/303/b/c/Meduzarts__Fallout_3___DC_by_I_NetGraFX.jpg. So it's a mixture of in-game content, photographic referencing, and digital painting.
EDIT: It's actually pretty easy to render off of Photographs after some practice. You already have the lighting and colors there for you to work off of, and you just need to make it fit into the big picture. You used a photo reference for the explosion in the background of your image, and then you have some photographed textures for your fur and armour. I would recommend painting on top of those, and to really build upon the atmosphere you want. Make those textures dirty, make them look like they belong in the scene. I would also recommend working out different poses. It kind of reminds of me of that video, "cool guys don't look at explosions". You also want to consider where you want the viewer to look. The first thing I see is the explosion in the background, then his face, then his sword, but the sword kind of guides you down to his crotch, and your eye kind of lingers there back and forth between the sword and the helmet. If I were to redo your image, I would leave the helmet on the ground, probably somewhere on th left, and then have him on the ground lifting himself up on his sword. I would also make the ground darker, make it look like the dragon got done or is in the process of scotching the landscape, maybe have a couple dead trees, I love drawing trees in my pictures.
Anyway, your anatomical knowledge is pretty good, Maybe the muscles are little to defined. The main thing I would recommend working on is your knowledge of light and shadow, along with not being afraid to paint or build on top of textures and images. Having some sharp transitions between light and dark really makes a picture stand out, and interesting to look at.