For receiving iMessages, I’d love to see something akin to the excellent , a menu bar utility that uses the Growl notification framework to provide you with notifications of text messages sent to your Google Voice number, and provides a simple interface for reading and responding to them. An app aimed more at iMessages might even be able to provide some client-side options for controlling who you’ll receive messages from on your Mac.

Another option would be to open up the iMessage protocol to other developers, letting them construct their own third-party clients for the Mac. Unfortunately, I don’t think that’s very likely, in part because Apple would then seem to be beholden to allowing the same thing on iOS. The precedent’s not exactly optimistic either: Apple said way back when it introduced FaceTime that —feel free to give me a shout if you’ve run into any third-party FaceTime clients lately.

If you’ve been paying careful attention—and I’m sure you have—you’ll have noticed a theme running through all of these points: control. For instant messaging, users are given a large degree of control. On the flipside, that also makes the software more complex, with a steeper learning curve; by comparison, text messaging is more or less drop-dead simple.

But even a meager degree of control on top of iMessage would be a welcome addition. Maybe Apple will head that direction in the future—perhaps even the final version of Messages that ships with Mountain Lion will have improvements over what we’ve been shown so far. Personally, I would be happy to simply have iMessages available on my Mac without having to deal with the misbegotten chimera that is Messages.