This seems sudden, but well timed given 2015's ICANN contract expiration with the Commerce department. It'll never be clear how much this had to do with Snowden's revelations and how much it was inevitable and planned anyway. Seems to me the Snowden revelations will impact the shape, to some extent, of the next phase of DNS and Internet governance. While the current DNS system has its flaws, its surely critical infrastructure, and I'm sure wiser minds than mine have planned and are planning to make sure a transition does not make anything materially worse. One hopes.
Anyway, this is a significant step, and one to keep an eye on as it influences the evolution of Internet governance.