My own personal opinion is that copyrighted graphics are a big no no. Temporary are going to be fine, but unless your gameplay really "wows" them it's going to be tough to win or even place without your whole game being pretty polished. But if you have to choose, go with placeholder graphics and avoid any that your ripped or borrowed.

Matthew Doucette:

If we cannot find graphics work, can we submit our game "concept" with temporary/copyrighted graphics?

By entering the Contest, each Participant/Team warrants that Participant's/Team's right to enter the Entry is not restricted in any way. In the event an Entry includes elements not owned by Participant/Team, then Participant/Team may be required to provide, if requested, a legal release for use of such elements, in a form satisfactory to judges such that Sponsor may use such elements, in whole or in part, and any modification thereof, in any and all media now known or hereinafter developed without territorial, time or any other limitation.

northwind999:

By the way, are we allowed to use the music files of the starter kits? I'm using 2-3 sound files of the Spacewar Starter Kit! Do I have to remove them? thx

Nick Gravelyn:

Matthew Doucette:

If we cannot find graphics work, can we submit our game "concept" with temporary/copyrighted graphics?

Absolutely not. You do not have permission to use them and the official rules clearly state you must have permission to use everything in your game:

By entering the Contest, each Participant/Team warrants that Participant's/Team's right to enter the Entry is not restricted in any way. In the event an Entry includes elements not owned by Participant/Team, then Participant/Team may be required to provide, if requested, a legal release for use of such elements, in a form satisfactory to judges such that Sponsor may use such elements, in whole or in part, and any modification thereof, in any and all media now known or hereinafter developed without territorial, time or any other limitation.

Useful Solution! - the net has a variety of works licensed by the http://creativecommons.org/ 

Question - how does Microsoft feel about assets that make use of a less formal means of saying "just put my name on it and tell me about it"?

FernandoRM:

Question - how does Microsoft feel about assets that make use of a less formal means of saying "just put my name on it and tell me about it"?

I think thats a very easy license to comply with...