Multi-platform category is a good one, and I'm all for it.

In a competition, especially with prizes, there is no common sense. If we want for the competition to go as smooth as it can, we need all the rules to be defined, so everybody is clear on them.

If we include only maemo/meego devices, most probably the winner will be the one with most of the devices, as without a physical device, porting becomes increasingly harder.

The less devices there are, a tie is more likelier. For which we'll also need rules.

IMHO, in competition we'll get what we ask for.
In the other categories we have the invisible hand of the crowd, that ensures some quality and necessity of applications.
If we look for bigger number of applications, we may end with a bunch of small, not so useful ones.

We should also define what is counted as a port. I know it's common sense, but the more the rules are defined the better in the end. They should have the same functionality. Everything has to work on all of them. And others. To not get into situation: it works... kinda.

Maybe we could combine the number of applications with a voting through some point system. Maybe 50-50 points, proportionally.
5 platforms, 10 points per platform.
10 applications, 5 points per place. 1st-50, 2nd-45...
Add points together, and compare.
This way, there would be some quality control, from the community.