Once popular, Skype, may be forced to shut down its operations due to voip patent disputes. Skype owner, EBAY, plans to go to trial with Joltid Limited in mid-2010. (Joltid licenses peer to peer technology to Skype.)
I presume if a settlement cannot be made, that EBAY will shutdown Skype. EBAY acquired Skype in late 2005 for $2.1 billion with the goal of leveraging Skype's 52 million registered users and 2 million paying customers for cross sell opportunities. It does not appear that EBAY has re-couped its $2.1B investment.
The Web Conferencing Expert