Not meaning to sound impartial, but there's not much special about the BlackBerry OS (RIM's disastrous performance of late must mean something.) Nothing much special, apart from BBM that is, or BlackBerry messenger for those not in the know. SMS is a relatively new technology and communication is changing and adapting to human needs and behaviour all the time, the BBM way of talking is probably the way things are going.
If you aren't aware of how BBM works the easiest way to describe it is, it's like MSN (or Windows Live as they call it now.) Rather than to pay for texts BBM allows BlackBerry users to message each other for free. It's also a smoother and quicker service than SMS and it confirms when a message has been read a bit like them delivery confirmation texts but without the full inbox.
Obviously the problem is that not everyone has a BlackBerry so it was only a matter of time before a cross-platform service emerged and here it is, already much hyped, liveprofile, is a fast and efficient message service downloadable from BlackBerry app world, Android market and even the Apple app store.
It's not my job to sell it to you but it is a very good service which some people will find very useful indeed. If you think you're one of those people check it out, here. It's free so it's worth a look. And remember, you heard it here first.