1. A building control and automation system for a premises, comprising: intelligent system elements, including: intelligent lighting devices each including a light source, intelligent utility building control and automation elements each including a controllable mechanism and associated drive electronics, and either a user interface component configured as a controller, or a sensor including a detector; wherein each respective intelligent system element further includes: (a) a communication interface configured to enable communication via a link of a data communication network at the premises; (b) a processor coupled to the light source, the drive electronics, the user interface component or the detector and coupled to communicate via the communication interface and the network link; (c) a memory accessible to the processor; and (d) programming in the memory which configures the processor to control operations of the respective intelligent system element as a lighting device, a utility building control and automation element, a controller or a sensor; and an instance of server programming stored in the memory of one of the intelligent lighting devices for execution by the processor of the intelligent lighting device, which configures the intelligent lighting device to implement a building control and automation system (BCAS) server function with respect to an overall building control and automation function of the system and related server communications with others of the intelligent system elements, via the data communication network, including for lighting and for other utility building control and automation functions.