I'm sure they are in the works. I think that is what people who think that imessenger is redundant are not understanding. Funny thing is I had to re activate my old bb storm because the droid charge got sold and the 4s hasn't made an appearance yet. I was going through some of my old stomping grounds on some of the forums from bbm. I chatted with people all across the globe. That's were imessenger comes in handy. Once those forums start popping up people will finally understand how huge this thing really is. It has the potential to put bbm to shame once it catches on across the globe.
I really hope they do come out with a group feature. iMessage is pretty pointless to me as is. I have unlimited text anyway so the fact that iMessage doesn't use your text allotment doesn't matter. I keep hearing that iMessage will revolutionize messaging on the iphone, but I'm not seeing it yet.