allow to create a new VM based on an existing managed disk instead from a template
to paint the picture- i had an issue recently where for my own fault a VM wouldnt boot anymore. it was amazingly easy to modify and fix the OS-disk by 1) deleting the dead VM and this way releasing its managed OS-disk 2) attach this now free disk to another VM as additional disk 3) boot the other vm where now drive E was the attached disk, change anything necessary 4) shut down the vm and detach that additional disk which should now boot flawlessly.....all this up to this point worked like a charm from the web-portal of azure. now for point 5 something is missing. i now had a group with everything necessary for the VM, the network-adapter,routing-configurations,the OS-disk...just no VM. so what i now wish existed: to create a new VM, but have the option to not choose one of the templates, but instead only choose the machine-size, pick the OS-disk that already exists, maybe also choose the existing network-adapter and everything that was left over from deleting the VM at the beginning, click OK and have a VM that can boot from the managed disk i already have. i know this missing steps are already today possible via powershell, but its not nearly as easy as it could and maybe should be. for someone having to fix a non booting system like i had, this additional feature would complete the picture quite nicely, because like i said- everything to fix the disk was amazingly easy and working like a charm, just then finally creating a VM again that runs and boots from that disk is sadly no more possible from the portal. i believe many in a similar situation would love to have this possibility.