AWS Transit Gateway was introduced during RE:Invent’18.
https://www.youtube.com/watch?v=ar6sLmJ45xs (MUST WATCH)
AWS Transit Gateway is a really nice new service and a powerful replacement to the VPC peering model and the transit VPC model with VPNs. It acts as a central point to control data transfers between VPCs and towards external resources. Available but with limitations as of Nov 2018. Amazon is working on finalizing support for AWS Direct Connect (Q1 ’19), multi-regions (TBD) and availability over all regions.
Once support for AWS Direct Connect is available, it will combine nicely with the new Route53 resolver to recognize on-premise Domain Names and a good replacement to the previous AD model.
Yes I think this is a long awaited service!