The short story is that Apple is moving the laptop line, and presumably desktops too, to ARM based chips as soon as possible. With A15/Eagle allowing more than 32-bit memory access, things look up, but it seems silly to do so before the full 64 bit cores come in the following generation. Nvidia is directly telling certain favored analysts that they will have Denver out in Q4 of 2012, maybe Q1/2013, and that uses the full on 64-bit ARM instruction set. It won’t be out by then, but that gives you a good estimation of when that ISA will break cover from one vendor or other. Think mid-2013.
You can read the full story here: http://semiaccurate.com/2011/05/05/apple-dumps-intel-from-laptop-lines/
Got to love the name of the source for this one: "Semi Accurate"!

Anyway, I won't read too much into this, although I'm not saying it won't happen. Feels a bit unlikely, they "just" jumped architecture afterall...
But I have said it many times before - ARM will scale upwards a lot easier than x86 will scale downwards. ARM will, backed by at least nVidia (who is making a "x86 killer" to use their own words) and Microsoft (who *already* have a complete Windows and Office running on ARM), compete with x86 at its own traditional arenas (desktop, server and workstation), but no x86 on horizon is really capable of competing with ARM in a similar manner.
I wouldn't be surprised if the next Xbox (720 or whatever it will be called) will be based on ARM.
