Then the question comes up, "How do we address the problem of Technology Injection?"
The answer is that the system has be well architected which promotes loose coupling, well defined functional requirements, and not deviating from non-functional capabilities. Each architecture should be flexible enough for change but change would be done in a phased approach. If the architecture is not flexible then be sure to have those big yellow stickers which say in menacing black print, "LEGACY SYSTEM", since you might need to use them in five to six years. Like any IT approach, research and development (R&D) and thorough technology analysis need to be done to identify which technologies can be safely injected into the system.