I just watched the Facebook live news-conference and now that Skype is going to be built into facebook, it very well could solve the problem that there is not a skype app out for the Playbook.
If anyone is on facebook and wants to give it a whirl, PM me and i'll add you on facebook and we'll see if it works
Unfortunately it seems to require a browser plugin to work on the PC. I wouldn't hold my breath waiting on the browser version to work in the Playbook browser.
On the other hand, maybe they will update the Playbook Facebook native app to support it. That would be sweet!