Obviously take this with a grain of salt but the veteran theme developers at Magmic seem to be getting a little closer to possibly getting themes on BlackBerry 7. In case you don’t know RIM has not yet shipped a Theme Builder for BlackBerry 7 claiming the theme system was broken by the Liquid Graphics engine in BlackBerry 7. They said they do have an internal theme builder but nothing for external devs until mid-2012.
That has not stopped Magmic product manager @PeterMacPhoto from trying. He let us know that they have managed to get some parts of themes loaded on BlackBerry 7. On the other hand it is not an easy process and has some caveats and limitations in their workaround. Still he said they are “close to getting some full themes together” which is promising!