Feels like after each update the iOS gets more and more complex to try and keep up with it's competitors, not sure if it's a good thing.
iMessage is an interesting addon, it shows that apple does feel blackberry have a winning application there. Will it steal away BBM users? Highly doubt it - Same reason whatsapp, gtalk and the many other chat programs haven't stole the BBM crowd.
The BIS (and cheaper alternatives of bb phones) is what makes BBM king, nothing quite like sending random pictures/movies and messages for "free".