Yes, they already have Messenger, and a desktop client to go with it. Or, I could just add my Yahoo! account to Messages on my Mac (as you can with your Google, AOL/Aim account, etc). Or on mobile, I can add it to any number of platform-agnostic messaging apps that behave the same way (though in my experience, the ones I've tried suck pretty badly). The difference is that NOW they're adding their own 1st party mobile client? That's the news? This warrants a press event?