The answer I would have gone with is if you wanted to keep the same desk was to use a KVM and have things separated. Others suggested Clever VM ideas which I think are pretty neat. However you're right. There's no separation of systems in case things go to crap on one and you need to use another pc as a plan-b or you need to quickly interrupt your recording session to do something on the Dev environment for whatever reason (say you received an inane phone call at 9 at night from someone you've been waiting all week to hear from, etc)..
In any case there has to be some form of partitioning between the systems, be it physical or logical. One system configured to do all will find more limits than dedicated equipment/systems for each specific task