It's still not quite as good as a native app, but it seems like you're getting 90% of the benefit with about 10% of the work. For a dev team strapped for resources it seems like a good option.
This would change everything, especially for the iPhone's walled gargen (unless new apps appear that require the extra power - perhaps console-quality games? complex visualizations)
Intel managed an amazing trick, of keeping demand for more processing power strong for decades (from 1978 to 1998; when the celeron was introduced, for the market that valued low price over performance; and 2008, the Atom for low power consumption over performance). But to really compete against ARM requires letting go of the blessing and the curse of back-compatibility - which Intel hasn't succeeded at so far (see Itanium). The demand for performance seems to be ending, and I expect with it, Intel will also - perhaps by 2018.
Perhaps Android is better in this regard?