I think you made my case for me.
HK416 is a reworked AR15 (design dates back to the late 1950's), that uses a short stroke system (already in use in WW2, as in the SVT-40)
Not familiar with the KAC E3 bolt. This is what I Googled just now.
http://www.militaryphotos.net/forums/showthread.php?144581-What-is-an-E3-bolt-and-how-does-it-work
Doesnt seem truly new, just slightly different.
When I think of "Greatest Innovation", I'm not thinking "Lets change the shape a bit, and paint it Desert Tan, and rename it Tactical Combat Battle Awesome Assault Tactical Weapon System Rifle!!!"
I'm thinking of the technology jump from bolter to self loading.
The "new" 6.8x43mm SPC is a great round, however it is suspiciously similar to the 7x43mm round proposed back in the early '50s for use in the EM-2 bullpup rifle
http://en.wikipedia.org/wiki/EM-2