Originally posted by Tony Belding There's an interesting point. A larger sensor might make sense if the camera then crops the image to different aspect ratios. That would be cool, as it would allow you to shoot various aspect ratios with minimum compromise. (I vaguely recall that at least one M4/3 camera, a Panasonic, already did this trick.)
However... The image circle projected by Q lenses isn't getting any bigger, nor should we want it to. Compactness is what the Q is all about, so it wouldn't make sense to compromise that.
The Q is for fun. If you need a compact camera, RX100 is much better bet. The 5-15 is quite large for the sensor size (It could be 5-15/1.8 as well), and E and NX systems have collapsible zoom which is much shorter.
If pentax decides to release 1" ILC camera, they might reuse Q mount for that so already existing adaptors work.
In the 1st model of Q, outer block with sensor is about 14x14 mm, which is more than enough to fit 1"