I have never heard of a similar app for bb either. Honestly, the reason is probably for security. BB is know for its rock solid stability and security. I am sure RIM doesn't want it opened up for hacking/modding.
Well, it sure would be handy to have the ability to manage most data on the PC and then upload to the BB. In order to do so, I believe one would have to delve into the device driver and make an appropriate interface with those API's.
I've not really checked into that, but may soon as I would like that added ease of use.
