Well, yeah. So what?
As an iOS user I'm salivating at the thought of actually being able to IM people properly. Right now invariably it goes something like this:
[push notification: you have a new message!]
[tap on notification]
[IM app launches]
[go get a coffee]
[IM app launched! Retrieving your new messages...]
[go get a sandwich]
[here's that message!]
Real multitasking is a huge win, even a diehard iOS user like myself will admit. I don't care if they had to summon Cthulhu to make it work - but as long as it does, it's a great selling point.