you can't run RouterOS in an OpenVZ container.
KVM is out because I don't have virtualised hardware. Xen seems to be out because a) Mikrotik have given up on it and, b) Ubuntu has given up on it. Now OpenVZ is out. Looks like I'm down to VBox or VMware.
Makes it easier, I suppose, like being able to have any colour Ford as long as it's black.