A Possible Solution to Messages Annoyances
/If you get a message sent to your freshly registered iMessage email address, you’ll get alerts on your Mac and any other devices simultaneously. If you have an iPhone, a Mac with Messages installed and an iPad, you’re getting three audio, visual and/or vibratory alerts for every message. After a few of these, you’ll start feeling like you’re in a pachinko parlor with beeps, bloops and flashes driving you nuts.
He continues, a little later:
To fix this, Apple could use a syncing service, say iCloud, or perhaps the Push Notification system that it already uses to facilitate the iMessage network, to determine when your Mac was active. If you’re noodling around on your Mac, and have Messages running, then it will send any iMessage alerts there.
These alerts will appear in the new Notification Center introduced in Mountain Lion, not on your devices. When you walk away from your Mac or it goes inactive for more than a couple of minutes, alerts will move back to your devices. It can even keep track and alert you retroactively from the moment that your cursor stopped moving. That way you never miss any alerts, even if a message was sent moments after you turned away from your Mac and walked away.
This idea has some merit. Especially if you're an avid texter (I'm not). It'll be interesting to see if Apple addresses this issue.