My bets are on Google.

www.pbs.org

There will not be one winner in this battle. Skype will probably remain the leader in computer to computer calls. Vonage will probably remain the leader in actual VoIP in homes. The other companies which have just entered the VoIP market are trying to copy Skype's business model but Skype seems to stay on the cutting edge (recentyl coming out with video calls via VoIP).

Dont be so quick to look for a winner? Not everything has a winner and a looser. Who won the battle over cell phone service? Who won the battle over basic news channels? Who won the battle over long distance carrier? Who won the battle of Coke vs Pepsi? Sometimes its nice to break things down to black and white, winners and loosers, but its not always practical. There might be a service that you like more, or is slightly more popular, but it wont be the only game in town. Did anyone win the search battle? or how about in homepage/portal pages? No, some are more practical for some people. But there will still be a few around.

Why does there have to be one winner? Last time one company won all the chips it created a monopoly called Microsoft with hugly inflated prices. Hopefully several companies will emerge.Don't forget SIPphone with their Gizmo software. www.sipphone.com

I'm not placing my money on any of the horses that use other ISP's bandwidth to make phone-to-phone type calls. As more and more cable providers start offering traditional phone services, I don't think it's a stretch to think they might start blocking the Vonage-type providers that are essentially offering the same service at the expense of their traffic.Believe me, I'm not making an ethical or moral judgement on this, but I've always wondered how long it will take broadband companies to cut off access to VoIP providers.

"...by the end of 2008 some 17.5 million users, or about 16 percent of U.S. homes, will be VOIPing -- the beginning of mass-market acceptance."the Yankee Group, Wall Street Week with FortuneMy guess is that 20 years from now we will all be using VOIP. All the phone, cable and internet companies are adding VOIP to their list of services. We will have MANY choices of who to get service from. I don't think it is a matter of who will win in the long run. It will be easy to stay in the industry. I would say it's more a matter of who's left after all the lawsuits (Vonage) and those that don't destroy themselves with bad spending practices (think dot bomb era).