My .02
Just some random thoughts from a biased person hoping for an update before 2016.
1. For Apple to do this interim update now I think they have some pretty good assurances from Intel as to when Skylake will be coming.
2. Just two years ago they did an update in February, followed by another update in October. So I think we can throw out any arguments that say October-December is too soon.
3. I think the next revision will bring the 13" and 15" back on the same upgrade cycle. That said, considering the 13" was updated at the beginning of March, it makes an update before the end of the year that much more plausible (assuming processor availability). As stated above, Apple has already shown they aren't opposed to a shorter upgrade cycle.
4. I don't think we'll see a huge chassis redesign. Ports may change and maybe they shave a few millimeters off, possibly color options. I don't think it will go to a Macbook/Macbook Air wedge shape.
5. Assuming availability. I wouldn't be surprised to see an announcement in October at Apple's iPad event (possibly along side iMac updates), with shipping dates a few weeks later in November.
