My understanding is the new Vnet-to-Vnet functionality allows for a hub and spoke design to be implemented . A single Vnet gateway can now be used to connect multiple Vnets to express route circuits or other services reducing the amount of G/W's and connections required.
My question is:
What happens if the Hub gateway fails, are all the Vnets connected to the hub isolated from the rest of the network?
Can a second HA gateway be configured as a hot standby?
The new functionality improves managabilty and latency but if it extends a single point of failure to many Vnets it limits the enviroments where it can be deployed.