I think one of the issues for M43 is that P&S like RX100 are able to reach close to DSLR quality already and are much smaller. It is only a matter of time before P&S have APSC or FF sensor. See the RX1. Sony only need to advance folding lens technology. To counter this M43 need to develop lenscap lens that has behind the lens elements that can fold out. This will allow it to be pocketable and retain possibility of interchangeable lens