it only means that it will be integrated with M$ office, which means :

you can call your mother on skype from your powerpoint presentation.
you can calculate in excel how many minutes you spent on a skype call and you will be sent a bill
You can type in word and it will be translated to voice, you can leave the transcript overnight and the chat will happen .... but you will have to pay for it

so its all about Dollars out of users not just by advertisement or revenue out phone calls.