RIM has just released the new BlackBerry Messenger 7.0 into the BlackBerry App World. Its key selling point is the free Wi-Fi calling, which lets you do calls to all other BBM 7.0 users for free.
Other new stuff coming up with the BBM 7.0 is the synchronization with your BlackBerry ID profile, 16 new emote icons and notifications when new version becomes available.
The BBM 7.0 is now available for the BB OS 7.x and 6.x users, while those stuck on OS 5.x need not worry. RIM is working on adding support for OS 5.x and will release a compatible version in the beginning of 2013. Sweet!