It's like 2015 is going to be remembered as the year when Apple set in motion for its in-house developed chips to replace Intel chips in Macs. This started with Apple using a relatively underpowered, by today's standard, Intel chip in the new Macbook as the much anticipated iPad Pro wait in the wings to be introduced with an updated iOS 9 more suitable for power users. And this iPad Pro will sport a brand new A-series chip with comparable computing power but a longer battery life than the Macbook.
In fact, the iPad, since the very first iPad introduced by Steve Jobs, have a longer battery life than most of the Macbook variants including this 12" Macbook.
One can assume, then, that Apple will allow this new Macbook battle it out on the market with the iPad Pro. Let the users decide what works better for them. A traditional laptop against tablet. Also, this won't be just an iPad with a bigger screen and a more powerful chip. Apple will probably accessorize the new iPad Pro with a cover that doubles as a keyboard, not unlike what we see with the Surface Pro from Microsoft (for discussions over Apple "copying" Microsoft in this regard, we'll leave it out for another day).
Of course, this is mostly speculation since there is hardly any concrete information about the iPad Pro, what features make it a pro version of the iPad, and if Apple will even release it (probably). For veteran Apple watchers, it is a well known fact Apple worked on many projects that never seen the light of day.
Once we know all about the Pro, then we can begin to gain a clearer picture about Apple's CPU going forward. There are discussions going on about how the 2015 Macbook was like the original Macbook Air when it was released. It was underpowered and overpriced. Perhaps this Macbook is. Perhaps not. But most agree that by the third iteration, it should be the Macbook that Apple wanted it to be. And it may be the replacement for the Macbook Air.
Let's wait and see six months from now when the new iPads are released. If the 2015 iPads are close in computing power or as powerful as the Macbook, it may well be that the iPads will eventually replace the consumer-class Macs.