I have been tasked with replacing our current network using Windows Server 2008 Virtual Machines running on Hyper-V, my question is will a DC as 1 VM work and a RODC as another work on the same machine?
I can't think of any reason why you couldn't run two domain controller VMs on the same host machine, one of them being a read-only domain controller (assuming you can deploy an RDOC in the first place).
Why would you do that, though? Typically, you'd be deploying an RDOC into a physical location like a branch office, or somewhere with poor physical security. Running both on the same host doesn't make much sense to me.