I have no inside knowledge, I have gotten no hints or clues from anyone on the web team. However, I have seen more than a few public posts where members of the web-team have stated that they are working on a next-stage of the site and a revised functionality and usefulness to groups. It's utter and complete speculation on my part, but if those changes in development and testing are really dramatic and could result in major revisions, I can at least imagine that the existing avatar and group theme formats may be changing. If that is the case (and it is a BIG if), having a contest that has people laboring to create new avatars and group themes that would then be rendered non-functional if/when the site is revised? Well, that could be seen as a "waste of my time" for the people who put a lot of effort into creating new avatars and/or group themes.