I think there will be new body introduced in a near future. Of course, not necessarily with the M mount module. The main reason why I think there will be new GXR body is new Phase Detection AF introduced with the CX5. CX5 is definitely not the target camera for this "new" feature. I rather consider CX range a test platform for more important cameras like GRD and newly GXR. Introduction of new body with integrated PD-AF would immediately speed up the AF of all existing modules, which is important mainly for A12 modules. All existing mirrorless cameras now use contrast detection based AF, which is not particularly fast. PD-AF is used by DSLRs in non-live view mode. This is why the DSLRs are much faster than all existing mirrorless cameras.
PD-AF is most probably not the only reason for new body. Support of new, faster and higher capacity SD cards is another reason, including the direct support for eye-fi wifi SD cards also introduced in CX5. And of course, there is a room for button layout redesign. I guess there is not many people using Direct button, just because of very odd button placement. The same apply for LCD/EVF button. And I definitely hope they will replace the ON/OFF switch with more common button