According to Reuters, the big idea is that the developers will help design applications for future smartphones that will run on a modified version of the software running RIM's poor-selling PlayBook tablet.
RIM has insisted that the gizmo was not the commercial BlackBerry 10 device, which will launch this year but would help create excitement among developers for its overhauled operating system.
RIM's social media manager Alex Kinsella said that while it is not the final hardware or OS it will help developers get started with designing for what's coming.
Starting with a new PlayBook and BlackBerry 10 with a different operating system than RIM's current BlackBerries will reduce the amount of available software still further.
The device, called the BlackBerry 10 Dev Alpha, will be given to developers attending RIM's annual BlackBerry World conference in May.