Dan Moren makes the case for iMessage and IM to be two separate apps on the Mac and for Apple to give users greater control over iMessage.
It’s an interesting problem, but I don’t think separating the two is the solution. iMessage is great and so is IM, and they are two very different communication methods, BUT one is the future and one is the past.
I would really like to see some stats on teenage usage of IM. My guess is that outside of Facebook Chat, barely any teenagers use something like iChat or AIM. Therefore, I see what Apple is doing as keeping the legacy support of IM for users like Moren and I, while adding in support for iMessages — something that teenagers (the future user base) is likely to be using today — thus making Messages a relevant app for more users.
Those of us that like IM, may not like iMessages, but I the opposite is true of teenagers today: they are all about texting and Facebook.