I'm kind of struggling for what this is good for besides giving switch vendors a reason to push needless IDF upgrades and technology vendors yet another upcharge option.
1 gig Ethernet is already overkill for just about every desktop purpose and still has some useful life left in many data center applications, especially for lower performance areas, even in network storage.
The only place it becomes somewhat weak is in heavy use AC wireless deployments where it can be truly taxed, but most often even these deployments the vast majority of use reverts to the average of typical cabled clients.
It also feels like a reason to keep prices artificially high on 10 gig copper. 1 gig was sky high expensive when it first came out, but quickly became commoditized and very soon nearly everything came with 1 gig ports. 10 gig base T seems like it's been out for ages but prices really haven't dropped nearly as fast and I can't quite figure out why, other than it's fast enough to cut port densities by at least half while still providing 5x or greater throughput of 1 gig ports in most server deployments (ie, if you had 4x 1 gig ports and switch to 2x 10 gig ports, you have 20 gig aggregate vs. 4 gig aggregate and single stream throughput 10x the 1 gig solution).
And as usual, vendors can't stand the idea of the customer buying half of what they did before and getting 5-10x more value than they used to.
I guess the new standards will be great, but only if they replace 1 gig wherever you used to expect 1 gig, ie, everywhere. Otherwise it's either irrelevant or a new way to pay higher prices for 25-50% of the performance you should be getting out of 10 gig at the price -- or higher -- you ought to be paying for 10 gig these days.