For many photography enthusiasts, the mirror-less systems are usually not a replacement but an alternative secondary system. The main differentiators are autofocus performance (adv DSLR), IQ and size (adv Mirrorless). Depending on which cameras are compared, the IQ gap can be rather close. IQ and AF performance gap is closing steadily which leaves size. I don't think mirror-less will kill off the point and shoot. I think it will kill off the lower tiers of the consumer DSLR.
I don't think mirrorless will kill off the high tier P&S simply because of the physical constraints of implementing an interchangeable lens mount. This is one case in which the simplicity of a fixed mount camera trumps.
I also don't think cell phones will kill off high tier P&S either. More than likely the lower tiered P&S will probably die off. The biggest differentiators here are long zoom optics (adv super zoom P&S) and convenience/integration (adv smart phone).
I personally, really like the G series owning G1 all through the G6. From there I ended up with the LX3 shortly before going with micro 4/3. I think the latest G series has very compelling features and performance for those that don't find interchangeable lenses are necessity. I may buy one used just for the heck of it.