I think this is a general problem with the way the Maemo Community / application repository works. It's very off topic, but have you heard of any ideas on how to get round this? (Or improve participation?)

One way would be to enforce an application available in Extras-Testing only, which once a day looks for software versions you have installed, which hasn't been voted on to Extras yet, and pops up and asks the user to either vote up or down (or click the "I know I should, but I won't take part in this voting right now").