As a rule of thumb, always put your avatar on the forum you are using, that way it never times out, unless the forum does (in which case, it doesn't matter ;p)
As for the wallpaper - its important to always create wallpapers at a 1920x1440 (or 1920x1200) if you actually plan on making a true widescreen one = without black bars) - that way, you can prune down to 1920x1080 (1080p) and to 1280x720 (720p) but also without problems to all wide-screen resolutions and 5:4 and 4:3 resolutions. Mainly because downscaling and trimming is always better than black bars which you can not avoid if you never made that part of the image to begin with. Of course for a wallpaper its kinda important to have black bars because people tend to have larger system bars nowadays and some even have "top" locked gui as well
Besides that - as a artist i gotta say that it isn't a wallpaper but a collage
A wallpaper has to be designed with the desktop in mind
- Thats a wallpaper
http://ere4s3r.deviantart.com/art/Oceanic-Tranquility-Wallpaper-97721322 (shameless self-plug) ,p
So, after I plugged my own wallpaper i have to give you kudos for a nice attempt
Though to make a full-blown AI War wallpaper just using the standard game sprites isn't a good idea (they are way too small). Though i am not sure what sort of wallpaper is good for AI War because there really isn't any full-screen dedicated artwork to showcase it, meaning no 3D-Models of ships you can render at larger resolutions and touch up. And if you'd make 3D-Models for a wallpaper they wouldn't fit with the pixel art of the game.. ah well
Not meaning ill with these comments .. just bored