Broadwell is due - Apple traditionally get early access to Intel Processors. Could this device finally be the Tablet (running iOS) / Docked Desktop (running MacOS) that should be technically possible. Apple use a native compiler for their iOS apps, so they can target different CPUs with the same API.
They could even do it with ARM A57 CPUs in reverse. We know that the ARM A57 Core is powerful and they have inhouse designers - with the advent of mSATA and very power efficient CPUs (ARM or Broadwell), the age of the Tablet / Laptop may be about to become blurred
They did this once with BlueBox/Yellow Box - Intel/PPC. And there is no reason they couldn't virtualise iOS and MacOS under a hyper visor.
If they keep the pixel density of the Ipad mini, this is an instabuy. Have been waiting for a big 4K Tablet to REALLY enjoy my National Geography, Jump Point and other magazines for many years now.