For developers who think their app is the best, you may want to get your entries into Red Gate's software competition (supported by Microsoft, evidently).
The contest is simple:
Write an app. Get it onto the Marketplace. Create a screencast tagged #WP7COMP. Then create your competition entry here. You could win $10,000. And your app's still yours. Three judging panels will each be asked which app will developers love most? The one they choose, wins.
Three panels = Three prizes = $30,000 total prize money.