Android already has Google Talk baked into every version of android on every phone. It's an app called "talk" in your app drawer. You can add friends who also have gmail and talk over data/wifi and it's very fast. I use it all the time.
I don't think Huddle will be the Android equivalent of BBM or iMessage, since it's only used to communicate with people in your G+ circles. However I do foresee Google Talk finally receiving some developer love and finally improving their rather stale gTalk app. And will probably integrate with G+.
