Extra-Exta read all about it, Skype For Business is coming back...well it is soft of. Basically, Microsoft has recognized that the Skype name has more credibility than Lync does so they're renaming Lync, Skype for Business. That's the crux of the story, that's untold in my view. Given that, this is as much a marketing decision as it is a business and engineering one. At the end of the day this looks like a defensive move to counter Google Apps and give Office and Office365 users from jumping ship. To me this may be the right move, but it may be too late.
Since Lync already offers instant messaging and audio calling with Skype users, something had to be added to make it interesting, so Skype for Business will add video calling and the Skype user directory making it possible to call any Skype user on any device so let's hope this works the otherway too.
The big hook though is how Microsoft is using Office 365 and its own Lync/S4B integration going forward. It's designed to thus rival Google Hangouts, which means Office365 needs a Switch like service to marry up to it. Basically, Skype is that service, sort of.
To me this makes me think that Lync for Mobile, becomes Skype. And with LTE, the mobile enterprise extension is created best via Office365 adding Lync/S4B vs. a premise installation, as MSFT will keep the updates flowing (yes we know how often they happen.)