Today Canon announced the new Canon 6D Mark II. I personally own the first generation 6D and have been very happy with it although there are a few shortcomings that this new 6D II version addresses.
Probably my biggest complaint about the first Generation 6D is the rather basic Auto Focus. It only has a group of 9 AF points clustered around the center focus point. Only the center is cross-type. The new 6D II has 45 AF points and ALL are cross-type. While still not as impressive as the 65 all cross type AF points on my 7D Mark II or the new 5D Mark IV, 45 all cross type AF points is still a huge improvement.
The sensor is improved from 20 Meg Pixels to 26 Mega Pixels on the 6D II. Not sure you'd see a real difference unless printing very large prints and honestly I've been very happy with the overall performance of the sensor on my First Generation 6D. I'd be interested to see some side-by-side pictures between 6D and 6D II. I suspect the new sensor will have better low light capability and probably better dynamic range.
The shooting speed is also improved from 4.5 Frames Per Second to 6.5 Frames Per second. Still not as impressive as the 10 FPS that my 7D II is capable of, but still a noticeable improvement.
Finally, the new 6D II has a fully articulating rear screen - a first for a Canon full frame camera. Canon has several crop-sensor cameras that have articulating screens, but this is the first time that they have put such a screen on a Full Frame camera. It is also a touch screen. The price for this new 6D II is $1999. The next step up is the Canon 5D Mark IV with admittedly more capability (4k video vs 1080p video for one) but it is $3500. By comparison, my 7D Mark II, which is a crop-frame camera, was $1800 when it came out, so $2K for a very capable Full Frame seems like a reasonable price point given the capabilities.
Read all about it here:
http://www.canonrumors.com/canon-officially-announces-the-eos-6d-mark-ii/