will Skype have to comply with US warrants?
Skype - once it is owned by a US company - will have to comply with (warranted and possibly un-warranted) US wiretaps and the 'concerned' calls from powerful (and well-lobbied) politicians who don't like something somebody is saying over Skype.
If you are concerned about MS, then you don't understand Homeland Security, the NSA, and the US Gov't very well...