I literally cannot fathom why anybody would expect 60fps to be any sort of standard going into the next generation. I can appreciate and sympathise with people who want it, but the logistics of being a standard are flimsy at best.
Next gen 60fps has no rational to be a standard any more than 360/PS3 60fps standard, and GCN/Xbox/PS2 60fps standard. It is exclusively up to the developer, and entirely relative to engine optimisation, design scope, and asset quality.
From now until the end of time, or until some technical limitation/requirement forces a 60fps standard, developers will make games that fluctuate all over the place. There will always be a developer who prioritises 60fps for smooth responsive gameplay (see: fighters), and there will always be a developer happy with 30fps with the advantage of more complex rendering and game scope.