Well, rumors like that are good for ooVoo but in reality, Skype on BB10 is likely to happen. It's not a technical thing, it's all about what Microsoft wants from RIM and that's why you're seeing the ooVoo news now.
You see, the last thing Microsoft wants to do is lose the audience for Skype to a rival, upstart service because they have too much invested in it, and have added more assets to the mix that help them move more towards being THE COMMUNICATIONS SERVICE across all device platforms. They added GroupMe and QIK as acquisitions, so ultimately they need to be on the third biggest OS, just as they need to be on iOS and Android.
My hunch is that RIM and Microsoft make peace on this and if not at launch, sometime right after, Skype appears on the new BB10 devices and more importantly, Microsoft continues to move towards a Lync-Skype interop and eventually one service for all communications. To get there, Skype/Microsoft will want at least one thing from RIM---access to BBM, the over the top messaging service. Add in Group Me, instant calling and all that MSFT now has inside Skype and you have the Enterprise's communicator that goes over carrier networks, works over private networks and ties into Lync.