Vlingo allows you to launch BlackBerry Messenger by voice (say: "Vlingo open BlackBerry Messenger").
Furthermore, please be aware that with Vlingo Everywhere, which allows you to speak to insert text virtually anywhere you can type on your BlackBerry, you can speak your BBM message, after which it will have to be sent manually (i.e. without using Vlingo).
However, at this time, Vlingo does not support integration with BlackBerry Messenger. There is currently no command to send messages through BBM. Furthermore, SafeReader is currently unable to play back messages from BBM.