Caporegime
Wouldn't be surprised, for the most part current Gen CPU's are sort of like this by accident, given that not all cores preform equally. Binning already segregates CPU's and software already prioritizes use of fast and slow cores for appropriate purposes.
Arm proved it works, so there really isn't a good reason for it to not exist on desktop. It will mean however that CPU's that preform well at multiple virtualization are going to become increasingly associated with server and workstation roles over Desktop going forward.
Not that any rumours which are over a year out really worth commenting on though.
On the desktop i would rather have big core, i don't need to save 2 Watts at idle but i would like to get my rendering done much sooner, or have more frames in my games.