Re: BBM vs IMessage
While I agree BBM is one of the best messengers available - it has many features that other messengers simply dont have - it is not accurate to say it is end-to-end encrypted out of the box.
Just to clarify for those that don't know, BBM is encrypted end to end out of the proverbial box.
You can purchase an added level of encryption if you wish, which is known as BBM protect.
It is encrypted with TLS to and from BB infrastructure, however, like facebook messenger, skype, snapchat and other similar services, BBM is not end-to-end encrypted such that the provider cannot access the message content when required by a warrant.
Between Blackberry 10 devices, an additional global key is used to further secure the data to and from the Blackberry Infrastructure. But again, this key does not prevent Blackberry from accessing the messages when required by a warrant.
The only way to get end-to-end encryption on BBM is to purchase BBM Protected from their enterprise store (as you already mention). This service adds a 2nd layer of encryption to the data (or 3rd layer in the case of BB10 to BB10 messages). Additionally, the encryption key exchange is brokered solely on the devices, providing end-to-end encryption which cannot be intercepted by the BB infrastructure.