They talk about this in the video (at 4'54") -- saying they try to avoid the g-word, calling it 'Faster Ethernet', and in practice you'll get 200-300Mbps.
True, but still faster than 100Mbps, which can be nice
You can already get more than 100Mbps out of a Raspberry Pi using a USB Link cable (aka Windows Transfer cable). They are less than $5 online and you get around 160Mbps on a Raspberry Pi 1 (haven't tried it on y Raspberry Pi 3 yet).
You can also use a gigabit USB adaptor to get the same ~300mbps speeds as the 3 B+ now enjoys.
No but it still triples the bandwidth over 10/100 over USB.
Only if you will not use USB for anything else.
Disappointed that there still isn't a dedicated Ethernet controller. I would rather have that at 100Mbps than "gigabit" over USB.
Why the downvotes? It's a legitimate criticism. USB Ethernet is slower and consumes more CPU cycles.
But it is cheap and good enough for the foundation's goals.