This isn't exactly how is sounds. Essentially, the Skype guys created Kazaa back in the day and promised to sell it to Morpheus-maker, Streamcast. Instead, they sold the product to Sharman Networks. Now that Skype is popular and eBay owns, it, Streamcast wants their right of first refusal back and is trying to grab a little cash out of a deal gone sour.
Streamcast is basically saying that the Skype boys fraudulently sold their software to Sharman in order to prevent P2P lawsuits from eating them alive, thereby breaking all previous deals.
The charges probably won't stick and the "file-sharing" industry is notoriously nasty and sketchy, so this was to be expected. More a PR move than a lawsuit, I'd wager.
Skype, Zennstrom, Friis Et Al Sued for RICO Violations [AndyAbramson]
The Streamcast vs. Skype Et Al Complaint [AndyAbramson]
Skype, Founders Charged With Racketeering [TechDirt]