BBM in the BlackBerry Beta Zone has received a decent update today. This is a very small release for a few beta testers and doesn't seem to have many changes to it except to fix some bugs and performance updates. It also adds the ability to add images in the group chat from the overflow menu. If you do install the beta, BlackBerry is warning that you may lose all your current chats.
If you were sent the email, download the beta from your phone's BlackBerry Beta Zone app. If you're not yet a member head on over to the BlackBerry Beta Zone and sign up now.