Over at the official Starcraft: Ghost website the current layout is using a picture by Joe Madureira! You can download the various sized wallpapers of it in their wallpaper section. Could Mad! be working for Blizzard Entertainment now instead of NCsoft?
Over at Joemadfan.com, Nathen was told that Joe Mad was indeed at this years E3 Expo and is planning on sending him some images from the new game he is working on.
There are many possibilities for what the new game he's working on is... maybe Joe was working for Swingin' Ape Studios that was recently bought by Blizzard (Plus they are the team working on Starcraft: Ghost)... or is he still with NCsoft? My personal bet is he is with Blizzard since his artwork is on the site and NCsoft hasn't announced any new games at E3 this week, but who knows maybe they just asked him for a commission.
In the end only time will tell and you'll hear about it here when I find out.
For higher-resolution images check out Starcraft: Ghosts Official website Wallpapers