It would be nice if you could expand a subnet without having to remove all of the cloud services and VMs from the subnet. In our case we will have to destroy all of our subnets to expand one subnet. This is very inconvenient (yes we opened a support ticket).
Additionally, make the tool available that the internal Microsoft support people use that creates a nice table of the various components of the subscription (I don't need to know datacenter, node, cluster). I've only seen snippets of the tables, but they are better than what I am getting from either management portal.
Finally, a high level, Visio-type, diagram with interactive drill-down would be great. At the very least allow me to see what VMs reside on a subnet.
Idea of subnet expansion is in review. The topology view showing VNets, subnets and VMs under that is now available through Netwatcher which was just announced to preview. More information here: https://azure.microsoft.com/en-us/updates/public-preview-network-watcher/
— Narayan [MSFT]
Paul Daly commented
Similarly, I'd also like to be able to contract the size of a subnet and reclaim unused address space assuming that all devices attached to the subnet got their IPs via DHCP. I realize that I may have to wait for the duration of the DHCP lease for the remaining clients to compact down into their new subnet.