BBM is obviously great. Many other apps have some of its features but BBM is the only one that has ALL of them in one package. Until another app is able to do all this and more, BBM still comes out on top. But how can it be improved? Maybe some of these features will be part of RIM's next leaked roadmap.
VoIP because there are instances that are better off with an actual good ol’ telephone conversation. Sometimes you just can’t properly have a lovers quarrel via BBM. And if you could make phone calls through BBM you wouldn’t even need the recipient’s phone number.
Video Sharing You can definitely send videos over BBM, but it has to be low quality (MMS Mode) in order for it to fit the capacity of transfer file sizes. An actual "send video" menu option would be nice.
Message Recall because of the instantaneous nature of instant messaging I don’t think that this is technically possible but it could be something users would like and use. Especially all those drunk texters out there, and there are many. Currently the only way to recall a sent BBM is to ensure it hasn’t been read by the recipient and then delete the contact and the chat altogether.
More Emoticons you really can’t get your mood and point across as well without fun emoticons. How can I properly relay my angry feelings or send a “crotch punch” without the proper visual representation of the said action or facial expression using punctuation marks and letters?