Yup, if the thermostat works like a switch or gives off a voltage to turn on/off. I have the one that has analog inputs, but it seems to be more a comparator then A/D. When I get a bit of time to play with it again, I'll see if I can get the Analog aspect to work with a simple thermistor and a few pots to cal the temp curve.
I like the idea of a *single* central controller. Syncing timers and such can be a bear. No fans if CO2 is on, no CO2 if lights are off, etc. You can do it all in one spot (though I got one to be used as a remote relay on the ModBus off a PLC that will be taking on a few home automation tasks)
I'm using a PLC and some x10 modules currently to control everything. And all on ethernet so I can access from the road via internet.