The update brings large contact images, bright colours and an interface that is consistent across the app. BlackBerry claims to have worked quite hard on bringing the latest UI design to its messenger. The newer version of BBM for Android is available only through BlackBerry Beta Zone which is meant for the registered ones only. BlackBerry wants to have a measure of customer response before going in for the final rollout and is doing exactly this.
Currently, the beta program is full with registered members and your best shot at trying the revamped version is through joining the wait list for the time being. There is no official word as to when the update will see a final release and we can expect it to launch within the next 4-6 weeks.