On some carriers such as Rogers, it is no longer necessary to have a BES subscription to run instant messaging.

WebMessenger and MobileSSH works on a Rogers 7280 with BlackberryOS 4.0.0.100 now. It is rumored that T-Mobile has already done the same (Still to be confirmed).

It is no longer necessary for consumers to use BES for instant messaging once you get BlackberryOS 4.x and the carrier is using BWC 4.x.