Lightstar pm’d me with this announcement he found:

“If you are good with Photoshop or are a photographer, this is your chance to get your work and your name in front of a global audience while retaining full rights to all your images. Send Microsoft your art or photography, and they might use it in the gallery, either as a wallpaper (a standalone desktop image) or a full theme (a set of desktop images and colors).
Here's how to send us your work:

• First, please review the guidelines to make sure what you're sending is the right size, the right format, and is appropriate for our site.
• Send us your work in email. Attach one image per email. If you send five pictures, send five emails.
• Don't zip or compress your art.
• Include this info in each email:
  -Your name (how you want to be credited)
  -A brief description of your art or photo
  -Your preferred contact email name
  -The address of your website, if you have one
• Click the Submit button below (this will launch your email program if you have one), or just use this address: winpgal@microsoft.com. By emailing your work to this address, you agree to the Terms of Use.
• Still have questions? Check out the FAQ.

Start sending your images. Maybe your theme will end up on the Most popular tab of the Windows 7 themes page!”

                                                                               -  http://www.winmatrix.com/forums/index.php?/topic/32876-send-your-images-to-microsoft-for-new-windows-7-themes-and-wallpapers/

Just be smart and copyright your picture to protect it!

Thanks, Master Lightstar !!!