Rated 5 out of 5 stars
Your idea is indeed very good! I am experimenting with this addon. So far this is my understanding:
Each tab (except the one you're currently) on kind of "hibernates" after the user specifies a "timeout".
Yes indeed, the memory consumption also seems to go down a bit. It is sad that "the memory leak in Firefox" legend still exists:(...
However, kudos to your addon! Only problem is I now open up a lot more tabs:)