If I was in school, out of work or otherwise had a lot of free time on my hands I might take a stab at it. It would be low risk. There probably isn't much competition out there so it would be easy to get noticed if you're quick to market. Maybe you could scrape together $1000 in sales. I can't help but think it will lead to quick and dirty, low quality apps and sloppy ports, if anything at all.
For anyone who has to make a more difficult choice about how to spend their time I can't see how this platform is even remotely appealing. The handsets are crap. The OS is old and busted. You can't even depend on consistent input methods between handsets. There's absolutely no buzz around anything RIM does these days. The only time I ever see them mentioned in the news it's another story about layoffs, how far they've fallen or both.
WP7 looks much more appealing than this. There are some slick looking phones, a mostly nice looking OS and I've actually seen them out in the wild. Still, even WP7 is a distant third place behind iOS and Android.
RIM would be irresponsible not to try this. They have to at least show a willingness to try to stay in business. They desperately need developers and they still have some cash. I can't think of a better way to entice developers. Unfortunately, this is too little too late. The time for this was back when Blackberry App World was first released.