RIM has made a fortune on BlackBerry devices that have taken a good thing and stuck with it, keeping push Email at the core of their business while ever so slowly introducing new designs and consumer-friendly features.  Newer BlackBerrys like the Pearl and Curve aren't exactly cutting-edge by today's industrial design features, but they're successful because they've added improved ergonomics and trendy features like a media player and camera to the proven BlackBerry formula.

Still, an empire's got to keep growing in order to survive in today's fast-changing world of consumer electronics.  So it should come as no surprise when reports surface of RIM working on designs for a touchscreen BlackBerry and, now, a Sidekick-like BlackBerry with a slide-out QWERTY board.  Unwired View has the details on RIM's latest patent application for the latter device, and even threw together some Photoshop mockups of what the possible BlackBerry 9000 handset could look like.  I like the idea of a larger screen with a widescreen mode and the possible combination of touchscreen navigation with the trackball that's proven itself so handy on the Curve and Pearl.  Especially if they could enable the thing to be used in right-handed and left-handed modes at the user's discretion.

Maybe we'll see something new from RIM at CTIA in a few weeks?

Meantime, you can check out Unwired View's thoughts on a sliding-QWERTY BlackBerry.