It looks like Microsoft might be trying to modify the way Skype works to make it possible to listen in on your conversations; and then potentially advertise to you based on what you’re chatting about. (I’m guessing)
I’d expect this from Google as advertising is their business, but Skype is traditionally known to be bulletproof and un-eavesdroppable. Others worry that this could be used by FBI, CIA, etc. to listen in on suspects using Skype.
This isn’t a big deal for most of us, but it’s one more reminder that law enforcement hates encryption, and if Microsoft makes Skype capable of this built-in-back-door then Skype can be considered not-so-private anymore.