Wow, thank you all for the strong responses! I've written down the teams so I can figure out priority based on who is in the DBP '08 and how simple what they need is. The easiest way for me to help you out is for you to e-mail me the assets you want replaced in the same format that they exist in your game. I started work on the simple projects yesterday, I've attached the two games before and after thumbnails.
(Projects that are outside the DBP '08 and simple are the next priority, then its long term projects outside DBP)
The left is the placeholder art for the menu screen, single player, and versus. On the right is what I sent back:

These are what the powerups for the game looked like:

I felt a Poker game should have poker chip power-ups:

Default starter kit space ship and gun provided from second project:

Replacements:


For a Rollercoaster game I only recieved a text description of the things that needed to be displayed.
Here is the Health/Energy/Score bar and Lives to the right of it:


Asked to create a menu/text box without any description. Provided (ignore yellow arrow):

Note to all teams that have contacted me:
Please understand that I will try to reach and help as many teams as I can. Do not take offense if your project takes time to reach. When I look at the assets provided I will be working first on the projects that I can come up with immediate solutions to, and are simpliest for me to execute. Also remember there is a thing called my life. I cannot dedicate 24/7 to free projects, I've got bills to pay and work for money is top priority. Thank you all, and on to helping the XNA community...
-Jon
Check out my XBL Gamertag if you want to game. (I always dig co-op)
Check out my web site if you want to see my art. (I'm all about the giant robots)