It’s a big red flag for me that this had to be co-developed by eBay and RIM.  Why is the huge userbase not enough to incentivize app development?  Why does RIM need to co-develop apps for their platform?  Piecing together previous things I read, I suspect it has to do with the Blackberry platform not having been designed for third party app development.

The official eBay for BlackBerry application, which was co-developed by eBay and RIM, includes features to search for, track, and buy an item from the smartphone

via eBay opens auction app for BlackBerry | The Download Blog – Download.com.