Group Instant Messaging?

[farnlc]

I manage a small group of employees who all have Blackberries and we use Blackberry Messenger group chat to stay connected and in sync. Now a couple of us are migrating to the Touch Pro 2 and obviously BB Messenger won't be an option. I have looked at the usuall messaging programs, google talk, AIM etc, but I can't seem to find an option that will allow both Blackberries and WM to connect to the same instant messaging program and talk in a group.

Can anyone help me out?

Much appreciated!