Some more old rumors:
…
However, it has recently been brought to our
attention that Leica has sent a letter to its customers informing them
that a full-frame M is, indeed, on the way. Furthermore, the letter
seems to indicate that the M8 upgrade program, announced at PMA, may
include swapping out the current APS-D sensor with a full-frame, 35mm
sized one.
The upgrade, which will cost 1,200 Euros, officially includes
a more “Leica-like” shutter and feel, as well as quality improvements
to both hardware and firmware. But according to this latest news, M8
owners might be able to take advantage of a future full-frame sensor.
…
Via Adorama