Take into consideration that your company may have deactivated the ability to add third party applications onto your device. With a corporate provided BB, they have access and control to everything you do on your device. If they want to not allow you to access App World, or to load any applications on the device, they can.
If I were you I'd talk to your IT Department before attempting to load a new OS onto your device. I had to do that once for one of our salesman's devices that was giving him fits, but I contacted my IT Department first to let them know, and also because you will have to reactivate on the Enterprise server.
