There are a few thoughts, as you can well imagine, floating around today on why eBay bought Skype. Some are truly insane, but some are pretty interesting i think.
Dan Gillmor thinks it's all about having customers presense online. He raises some good points about the closed doors on Skype's crypto, and subsequent privacy issues aswell.
Dana thinks it's simply proof of the 2005 internet bubble. Maybe he's having a bad day, there's way more to it that THAT.
Ross thinks it's about conversations and markets. This fits well with me the most i think - eBay customers do much talking outside of "band", eBay want to enable them to communicate outside of the auction norms in a fashion controlled/enabled by them.
I also saw one opinion, just one, that said it was all about pay per call - (ish) - but it got lost somewhere heh.. Lots of voip in Search at the moment as it adds all kinds of interesting things to the mix: Presense, stickiness, ad ops, AND PPCall openings - maybe something in that, though i'd bet Ross has the right of it...