This new ThinkPad portable for professionals features a 6th generation Intel Core i7 processor, a 3K IPS display, and can provide up to 17 hours of autonomy on a single charge.
http://www.notebookcheck.net/Lenovo-unveils-ThinkPad-P50s-mobile-workstation.155136.0.html
No 4K display option :(
Unfortunately not, but 3K should be fine enough. Too bad you can't get 3K AND touchscreen, since the touchscreen variant only has full HD resolution. I think that's worse than just not having 4K.
Check out the pictures. It looks extremely close to the W550s, except the VGA port is replaced with a HDMI. Looking at the spec sheet, the 32GB ram and the internal+external battery setting, etc. pretty much confirm this is the successor of W550s.