Massivly on the fence with this but see a use so well prepared for all the downvotes to come pouring in...
This wont work for everyone and I expect it would run alongside traditional thick versions of windows, but its a choice...
Google has shown the chromebook has legs, this is just a Redmondised version.
Azure and AWS, etc shows that virtualising and cloud hosting server hardware is viable.
Everything is Subscription, so instead of my yearly OVS i pay a different subscription.
Fixed broadband speeds are going up and up, mobile broadband is getting cheaper,
Newer mobile hardware will have embedded broadband.
It has the possibility of extending hardware lifecycles, but to be honest, I think the 3yr cycle has long gone. A 4th Gen core processor with even a SATA SSD is more than capable of most general purpose office desktop/laptop tasks.
connecting over a VPN to a secured cloud based client will help with both physical security and DLP...
Problem with ol computers, after 7 years they are way out of warranty and more prone to hardware issues... but with a virtualised environment, issue another thin client and away they go - minimal downtime.
there will be the odd dead spot for mobile users, but this is the case with phones and chromebooks too...
Environmental, yes if I dont replace all my machines every x years thats less machines being made and less being recycled, as for power... more efficient use of centralised processing could offset the cost of connecting and idle client hardware, but i think energy savings will be minimal just as mentioned previously the point of emission has been shifted to someone else.