I use Skype all the time, and it is one of the best telephony products I have ever used. It was amazing when I could use it with my 12"powerbook in Singapore's Changi airport.. to talk to my wife back home in California.. for a super low rate. Its worked everywhere I've been and its functionality is not going to change by ebay buying it. I mean, why does everyone run for cover when they hear that ebay took over a company? Ebay is not going to ruin the company, is it?
I would think they could use Skype as a phone service for ebay sellers (powersellers) as some sort of customer service number that buyers can use to call (at discounted rates) Just like a live chat application..except that this would be a live 'call' app. Picture yourself looking at an auction.. and at the bottom there's a "Click here to talk to the seller" skype button.. You click on it and you can communicate with the seller regarding the product, etc. I would guess thats one way ebay would use skype.