I also interested in to see some sprinkler and heating devices in the LMCE. It can be done by following way. First of all it should be added a simple devices such sprinkler, turbine, pump etc into clime area to be able visible on the Orbiter. The next step is implementing a support of controllers such Rain8. It can be done using GSD or as plug-in (it's a bit harder). But the most difficult part is to implement software to manage schedule in the controller. As I know Rain8 can be programmed via Windows based commercial software. Sure the schedule can be prepared as a set of events but it's not so flexible and handy for the end-of-users.
We're developing out own solution based on ICPDAS controller. It'll provide a web interface to create the schedule. LMCE will just display the status of each sprinkler and will allows to switch it ON/OFF manually. The interface between controller and LMCE will be done as GSD device. So, we miss only elementary devices in LMCE - prinkler, turbine, pump.