Here is an interesting idea for a regime filter from William Delwiche:
The BAA Corporate Yield in Norgate is %COBAA. I tried it on my systems, and it managed ok with a shorter 3-month MA or longer 12-month MA on the US Monthly systems. Not as a good as my current regime filter though. Not great on the mean reversion systems.
Someone else might be able to find it useful (perhaps with an All Weather system?)