I still use both a BlackBerry and an Android device (helps with development). Part of the issue is that many people think of BBM as just another messenger service. It actually has a lot of added features:
- Send/Delivered/Read confirmations.
- Send text, pictures, voice messages...
- SMS contacts can be added into BBM for communicating from one list (chat to both BBM and SMS contacts from within BBM).
- BBM Groups for social networking.
- BBM Group calendar for sharing events.
- BBM Group lists can be used for to-do lists, grocery lists, assigned tasks.
- Games and apps can communicate via BBM.
- BBM7 adds voice calls between BBM contacts (over wifi).
- BB10 adds video chat to BBM.
A lot of what can be done through BBM can be emulated through various apps on Android. From all the different chat platforms (G+, GT, GV, Whatsapp, Kik...), to sharing a Google Calendar, most of it is covered (although I keep looking for a good group app). It would be nice if Google integrated their communication apps into one system, but until that happens, there is usually enough memory on current Android devices to handle loading up the ones you need for communicating with your group of friends and family. That, in itself, is a nice benefit of Android - flexibility to communicate with just about every platform.