Do Mediator and MindView run on terminal servers?

For the most part yes. Some elements such as audio playback and -capture may not function, but the visual elements and design interfaces for both programs work on terminal servers when running with a minimum of 256 colors.

Using the applications via terminal services may put a high load on the network due to the highly dynamic and graphic interfaces, and operating the application may be slower than if run locally. Keep in mind, that the higher the color count, the more data will have to be transferred.