Some 08's have it, mine does. While at an idle or when the engine is not running with the key on, I can roll the throttle forward and the hold it, the cruise light will blink either green (enabled) or orange (disabled) for the temp management system.
My friends 09' Roadglide appears to be the same.
From what I found out you can't just roll the throttle forward and it shuts off the rear cylinder. I have heard this from others thinking this is the way it works. On my bike when I roll the throttle forward and hold it for a few seconds it only enables or disables the temp system. I tried it on the 09 and it didn't shut off the cylinder either. So If anyone had actually been able to shut the cylinder off by just holding the throttle forward, please post it and let me know.
Either way when the system is enabled and running on only the front, If you shut it off by rolling the throttle forward it instantly goes into running on both cylinders, "IF" the engine is hot enough to already be in the single cylinder mode and you don't have the temp system on, it will go into single cylinder mode when you roll the throttle forward.
That is what I have found.