At today's BlackBerry Jam keynote sessions (a parallel conference to BlackBerry World this year), RIM announced that developers who create a BB10 app and turn in their BlackBerry 10 Dev Alpha prototype will receive a "limited edition" final BB10 smartphone in exchange, reports CrackBerry on Twitter.

We spoke to RIM about the arrangement, which might seem strange given that developers will already have the Dev Alpha device. However, it turns out that this prototype will likely never receive the final, shipping version of BlackBerry 10 when it launches, instead it will receive periodic updates between now and then that add some of the features of BB10 as RIM is ready to roll them out to developers. We're pretty sure that RIM's efforts to court developers would have taken a pretty serious hit had those developers discovered that these devices would not run the shipping version of BB10, so the arrangement to give them new devices at launch makes sense.

The news follows RIM's other developer-boosting announcement, a guarantee that developers will make at least $10,000 in sales in the first year, assuming the app meets certain minimum requirements.