Either that or they are just trying to pump up their stock price for the BlackBerry 10 launch so that the executives can dump their stock before the company goes bankrupt.
The $10k revenue guarantee is a hedge. They're betting that if you make an app that satisfies their Built for BlackBerry criteria (see: https://developer.blackberry.com/builtforblackberry/document...), it's good enough to sell 100 copies, and make at least $1k in revenue, then it's good enough to make $10k in revenue.
They're hoping that your app will be so awesome that they won't have to pay you anything. Bear in mind, this guarantee is over a 12-month period, so there's plenty of time to make that $10k on your own. Furthermore, by being Built for BlackBerry, you get special exposure in the App World storefront.
Personally, I think it's a fantastic idea, and I'm definitely going to be submitting an app or two. But I think a lot of people are taking it as "RIM is paying devs $10k to make an app." That simply isn't true. They're making you work for it, and then saying, "If after all of this work, you still don't make $10k, we'll front you the rest."
So the incentive to promote your app past $1,000 in revenue is that if you're putting in this much work, you should really try to maximize your return.
Then there are the junk apps that live at the bottom of the list. These come in huge hordes, and are worthless. RIM doesn't want to pay for them and doesn't care about having them. They provide no value to Apple or Google either.
But then there's a comparatively small group of "cool" apps that make everything work. This is the stuff that potential RIM customers notice is "missing". And the authors would love to see an extra $10k in sales, maybe enough to consider a port. And there aren't that many of them -- maybe a few thousand at most. So RIM is betting that if they blow a few million dollars on seeding this market that they'll make that back in extra handset sales in the near term. It might work.
But I don't think they're at risk of losing a ton of money. How many apps actually make that much even on "first tier" platforms?