If you're looking to run a successful developer program, you should probably pay attention to Mathys van Abbe. He's the founder of Mobypicture (our Mobypicture API profile), which has just celebrated its 500th developer.
If you have ever wanted to create photo mashups using Google's Picasa, now you can. As Sven Mawson of Picasa Web Albums Team announced there is now a GData API for Picasa. Media mashups are hot: as we noted in our piece on 200 Photo Mashups, photography-related mashups are one of the most popular genres.