The Law of Software Entropy as described by Ivar Jacobson et al. in "Object-Oriented Software Engineering: A Use Case Driven Approach": The second law of thermodynamics, in principle, st...
agreed. It's this principle that has led several companies I've talked to that use virtual machines for applications to NEVER make a change to a production server. If changes are necessary, a new server is deployed and the old is decommissioned. One of the many benefits of virtualization, and an even greater plug for orchestration via chef/puppet like recipes.