You can read the full text of the federal regulation here. Since this is clarifying a rule that's already on the books, this now raises questions about other parks, too. The cited regulation applies to all "persons, property, and natural and cultural resources within areas under the jurisdiction of the National Park Service." Which means there's a good chance that drone photography is banned at all National Parks. For Yosemite it makes a lot of sense, as these flying machines can create a lot of noise and air displacement, and could easily disturb local wildlife.