That would be great. I have some extensions that can cause bugs or slow load times on certain sites. So it would be nice to have a quick enable/disable option that does not remove the extension's toolbar shortcut and saves the hassle of tracking it down in the disabled catalog later.
Personally, I don't even need a filter list for certain sites or anything, because I actually do use these extensions on the sites they have issues with on occasion. So just an off/on switch would work for me.
Sad that it's been a year since this issue was brought up. Seems like an easy enough thing to add, from my limited-amateur coding eyes.