Andy refers us to a letter Michael Robertson (CEO of Gizmo) sent to Chris Libertelli at Skype. In part, it says:
[in regards to Skype demanding that wireless companies open their networks], Skype’s actions do not mirror their words to the commission which diminishes credibility for Skype to demand openness.
It appears that when it is convenient for Skype’s business objectives Skype waves the flag of openness, at the same time conveniently ignoring competitors requests for openness.
Here, here. You can read the entire letter over at Andy’s site.