I have a problem with Microsoft buying Skype. Skypes big selling point seems to be the fact that you can communicate with anyone anywhere in the world. If Microsoft buys Skype, you'll have to tack on "anyone anywhere in the world running Microsoft Windows", and that will kill the product.
Of course, if Facebook buys Skype, you'll have to sign-up for a facebook account. They'll probably record all your conversations too, just cause their TOS will allow it.
I don't know, Skype should go public, or not enter into some sort of exclusive agreement. Anything that closes-off skype to a percentage of the users out there would destroy it.