Ok I just see this...

Don’t throw away your HDMI cables

As mentioned above, HDMI 2.0a changes nothing about the size, shape, or wiring of HDMI cables. Should you wind up getting devices that are HDMI 2.0a compliant, your existing cables will work just fine. And since HDMI 2.0a is backward compatible with older HDMI versions, you’ll be able to connect your old Blu-ray player and/or AV receiver to a brand new HDMI 2.0a-equipped 4K Ultra HD TV with absolutely no problem.

So it's only the socket and nothing to do with the cable?? it just uses extra pins or lines on the actual cable to achieve the extra bandwidth and features.

EDIT

High-speed with Ethernet
High-speed without Ethernet

YOU NEED THESE FOR 4K

SCART is obviously no longer supported in anyway shape or form in this new standard of UHD TV.

I know that DVI-D carries the return audio pin so I think it's safe to assume that extra pins can be utilized on a DVI-D and turned to HDMI and possible work with HDMI 2.0 Compliant devices.

HDSDI to HDMI will no doubt have to go on the standard HDMI inputs as it's only 720P

I wonder if though if certain adaptors or turn arounds are not wired to make use of the extra pins so in effect rendering them useless if they are only wired depending on the different standards of HDMI 1.0 ,1.4 and 2.0a.

Some more quick notes on how we are being conned!!!

Manufacturers claiming to sell superior cabling when infact they are selling you the same cable as you would normally buy just with "This is a 4K cable printed on it" and charge you more money!!!!

Blu-rays labelled "Mastered in 4K" whilst superior they are in a resolution of 1080P they are not lying but it is a twist of the truth and misdirection whilst exposing the previous comment about "Crappy print scans" of current generation Blu-rays and selling you short on what you could have had already previously.