The latest illustration below found on the net has included all the current/existing ILDC system sensors for size comparison purpose, from the smallest 1/2.3" Pentax Q's up to the 135 FF:-
(Source: http://forum.xitek.com/showthread.php?threadid=900517)
So, we have seen once again how small the Q sensor actually is! ..Even when it is compared to the 4/3, Just! (And not even mention the APS-C!) >:-[
Afterall, if the Nikon and Fuji rumours are true, both will just blow the Pentax so easily out of water for the IQ, just because their sensors are still much larger! :-o
Last Related:-
Nikon Mirrorless Will Have a Larger Sensor Than the Q
How Large a Sensor that Pentax Could Put Into the Q?