The combination of Raspberry Pi and OpenSprinkler seems to be working quite well.
I posted the steps I used to get the pi and OpenSprinkler working together on my blog. At this point the Pi serves the JaveScript files and icons for the UI and handles logging of irrigation events.
I am in the process of writing a python module for interacting with OpenSprinkler. It will allow to write python programs which can be run on the Pi or other computer on the network that will be able to check and set irrigation schedules on OpenSprinkler. So far I have python functions that can change the Water Level %, set Rain Delay, read and change Run-Once Program settings and do things like set manual mode, reboot, and dis/enable OpenSprinkler. Once the module is ready I will be able to start working on some programs that tweak irrigation schedules based on evapotranspiration (ET) estimates from a local weather station. I will post here when the python module is available.
Dan