Here are some Palm stats: 85,000 SDK Downloads, 108 countries and 20,000 registrations for Project Aries online development environment. But yes, they're opening it up to the public today. Updating live.
Every developer can submit their app to Palm for distribution in Palm's 7 markets. Today, Palm has 1000 applications.
Palm's also making a system where you can make catalogues of Palm's apps - all open source - so people can take this and create catalogues of their own. I guess, for making top Palm app lists easily.
Palm just said they would give $US1 million - not sure how it's split - to the apps with the most downloads in both paid and free categories.