Why is there still a macbook air?
IMO the MacBook is an addition to the product line which I believe is somewhat like a "netbook" and the Air line is somewhere between "netbook" and MacBook Pro line. The MacBook uses a Broadwell Mobile Processor and the Air is using Broadwell i5 and i7 processors. There are many comparisons on the Internet even though the MacBook hasn't been released yet. Here is one example of a comparison. http://www.digitaltrends.com/computing/macbook-2015-vs-macbook-air-2015-spec-showdown/