[dishe]

Its not possible on a fundamental level.

It would be like trying to install Mac OS on your TI 89 Graphic Calculator. The platforms and hardware are so fundamentally different that its not even a question of "has anyone tried it", its just not possible. The TI is a calculating machine and the Mac OS is a fully fledged computing system.
However, you can install and run a TI 89 emulator on the Macintosh computer so that it looks like there is a graphic calculator pasted onto your screen, and it will run all the same commands and programs.

The Blackberry is a very basic device- it does what it does extremely well (hence the popularity of it) but it is no where near as sophisticated a device as a Pocket PC. The Pocket PC can emulate it, however, with proper software. However, there is no way on earth that a system as simple as a BB can emulate a fully fledged PDA OS like Windows Mobile or even Palm!