I believe they already have if this article is correct:
Skype uses peer-to-peer instead of traditional client/server connections to make the calls happen though. Since there's no sole middleman the data needs to know where it's going between each peer through an ip address. A traditional server can have both users connected and control the flow of information so that the IP isn't exposed to either user.
I am curious what this fix does to circumvent needing the destination IP address. Someone else could probably clarify better.