Not really mate, they want to take on whatsapp wich is now subscription based for new users plus bbm on iOS and Android will make possible for people that use Blackberrys with only "Social" data plan (only use bbm and email with no full data plan) to communicate with Android and iOS at no cost.
I can see them going after the current messaging services (using BBM, but without the BB). That's fine. They can become a software company. But I still don't get the option of having a BB communicate with an Android device or iPhone. People need to own BBs to make that happen. And while you may know someone with a BB (likely a 55 year-old white male who uses it as a work phone), the actual numbers say these phones are rare and on the path to extinction.