James Duncan Davidson notices that Messages is getting better at working across multiple devices:
In the small but lovely improvements department, iMessage support in iOS 6 and OS X 10.8.2 seems to finally smooth out many of the rough edges that it has sported since arriving last year. The ability to receive messages to your phone number on all your clients is the well-publicized part of this. More subtle—and much more welcome in my book—is the fact that iMessage now seems to sort out which client you’re using and keep the rest from dinging extraneously.
I’ve noticed the same thing—if I’m on my Mac and a message comes in while Messages is in the foreground or I bring it to the foreground within a certain amount of time, my iPhone and iPad don’t pop up notifications for it. It seems to work the same for opening messages on my iPad or iPhone, too.
Apple’s iMessage has had quite a few issues, but it’s improving quite nicely. It’s a wonderful thing to have continuous conversations across my Mac, iPhone and iPad. It’s getting so good that it’s almost entirely replaced instant messaging for me for conversations with certain people.
If it’s an indication for how iCloud and Siri are developing, then we should be quite happy, too. Apple seems to be getting better at this whole web services thing.