MacBook Air with ARM+Intel processors

Not sure how feasible this idea is but here it is. Imagine a MacBook Pro Air with Intels new Haswell processor used for intensive programs like Final Cut Pro and Photoshop and when those programs aren't in use the Air switches to Apple's new A6X for web browsing and light photo editing. The potential gain in battery life could be huge! I think apple has the resources to make this idea possible.