It's interesting to see the rise of the 1in sensor in the camera market at the moment, it's one that Nikon initially tried with their 1 series interchangeable lens cameras but largely failed as they couldn't seem to work the balance of the 1in sensor - the 1in sensor is smaller than the micro 4/3 sensor Panasonic and Olympus use but Nikon were unable to shrink the body and lenses to give an advantage for that smaller sensor size. Samsung tried their hand at a mirrorless 1in system as well with the NX Mini as well later on but also failed to produce a size advantage from the smaller sensor.
Sony however showed the potential for the 1in sensor size with their original RX100, a small compact camera that had a much larger sensor than the 1/1.7in sensors (like the Panasonic LX series) yet still managed a fast lens and a reasonable zoom range. Frequently the catch with shrinking down bodies with large sensors is that to make the lens small they either have to make a limited zoom range and dim aperture or a fixed prime lens with a brighter aperture. Sony have gently evolved the RX100 through to the mark 4 and have since brought back proper bridge cameras (most current bridge cameras have tiny sensors to allow them their huge zoom ranges) with the RX10 mk1 and mk2 using the RX100 internals but a larger body and zoom.
Panasonic really started the enthusiast market with the LX3 which had a larger sensor and brighter lens yet they've been oddly slow to join in with the 1in sensors however they have the FZ1000 bridge camera to rival the RX10 and recently announced a compact which looks very impressive as it boasts a staggering 25-250mm zoom range. It does make some compromises as it's aperture is F2.8-F5.9 but even then that's pretty good going for a compact with an EVF and some nice features like 4K video.
Canon were fairly quick to offer their own RX100 rival with the G7X and now recently announced the G7X mk2.
Nikon have recently jumped back into the 1in sensor with all guns blazing offering not just a compact and bridge camera with a 1in sensor but an interesting ultra wide compact that has an 18-50mm lens:http://www.dpreview.com/articles/203248 ... l-compacts
The two compacts are both fixed lens cameras so the 18-50mm choice is very unusual, comparatively the current RX100 is a 24-70mm so it's a fairly short range already only going to 70mm so 50mm is very short but it's probably not that much work for them to produce the second variant and there's nothing else out there like it in that size range.
For compacts, I think the 1in sensor is superb as it finally offers the balance of size and image quality I've been after for a long time as normal compacts were too big a drop from the bigger cameras and micro 4/3 cameras weren't quite small enough and meant either a slow zoom or a fast prime.
For bridge cameras though I'm not so sure, I bought the RX10 mk 2 when Amazon had 30% off warehouse items and got one that looks brand new and unused. Primarily I wanted it for the super slow motion which it shares with the RX100 mk4 and I love it on that, the RX10mk2 has the advantage of a 200mm range still at a relatively fast F2.8. I've been undecided about the camera though since I bought it and haven't actually used it until today, the problem is that while it has the 1in sensor instead of being very compact it's actually quite a big device, bigger than the Sony NEX-6 and 18-200mm despite the latter having a much bigger APS-C sensor. However the flip side is that the RX10m2 is a really well designed camera, when you pick it up everything just feels right about it and it has a nice range of controls including a zoom lever around the shutter button as well as a ring on the lens, an aperture ring (with a switch to have it click through F-stops or rotate smoothly), a little LCD on the top and the zoom action is really smooth in video mode. Comparatively the NEX-6/18-200mm has terrible handling as the body is too small and the lens too large plus the zoom ring is a standard mechanical one which means no smooth zooming in video mode. There is a power zoom version of 18-200mm lens but it's even bigger which has put me off that idea.