Not really a developer (only three sites for myself), but this would be a great idea. Although, like DD32, figuring out which plugins to use is the biggest problem. Trying to get used to coding styles, community around plugin and whether the developer will stick with it (are they compensated - monetarily or otherwise).

Wordpress.org could do some things other than downloads and ratings to help with this. Heck, even the Google custom search I have to check "freshness" of plugins is a start.