Well its not really that successful compared to others probably because RIM could not attract decent developers with Adobe AIR SDK (basically Flash), but those few users are craving for good games and they pay!
The main reason I am suggesting it other than that I do own one is because porting C++ code should be easy:
Quote: "The BlackBerry Native SDK for Tablet OS provides game developers with a native C/C++ mobile development environment. It provides access to Open GL ES 2.0 for 2D and 3D programming, and is POSIX compliant, enabling efficient and easy portability of existing games to the BlackBerry Tablet OS."
http://03268fe.netsolhost.com/bbbeta/
It still has a chance to jump with the native SDK, as it has high specs (dual core processor, 1 GB ram) and can compete with any other tablet out there, especially with its low price compared to the quality.
Plus RIM are doing their best to attract developers with development contests, free devices, free registration and submission.
I'm back