All CSU single engine types I know default to fine pitch/high RPM and use oil pressure to drive against the strong CTM causing the fine pitch tendency. This means that a failure of the governing system still leaves full power available.
Light multi-engine a/c with feathering props use some combination of counterweights/feathering spring/pressurised gas or oil in combination with the ATM to overpower the CTM. This causes the prop. to default to coarse pitch/low RPM and eventually into feather.
A failure of the governing system/engine at least allows the failed unit to be feathered to reduce drag for the remaining engine.
There is a slight problem introduced by this feathering system in that the prop will try to go into feather when oil pressure is lost after the engine is shutdown normally. Not good for then next start!. This problem is prevented by latches that engage when RPM drops below a certain critical value (typically 800 or 1000 RPM or so). Given a real engine failure, it's important to identify if the RPM is reducing in any immediate actions so feathering can be done before the ability gets locked out.
[ 08 July 2001: Message edited by: Tinstaafl ]