For the multi platform competition I can see several problems.

I could be a dick, monitor the applications that are in the competition and do the minimal amount of porting to have the same amount as the one that has the most, and do it for the same platforms.

Then there is I could make an iFart for many platforms, and win because it's a simple application, and probably easier to port then something that requires hardware integration, like accelerometer, camera or other.

Maybe there should be platforms defined in advanced, and/or a good definition what a platform means in this context.
If it working on desktop, is it one platform or three (windows, mac and linux, maybe others BSD). I'm assuming as we're mentioning fremantle and harmattan, the latter.
If desktop is excluded and we go only for mobile world. Do we take into consideration android, iOS, bada and others?

IMHO this category should be well defined as it's a hornets nest,