Honestly, I'd prefer a heuristic that could determine whether https was significant on the current URL. Are there submitted values, cookies of importance, get parameters? There are a lot of reasons https is important and there are a lot of places where it's totally not important.

If you draw people's attention to something that isn't seriously important, then those times when the whole screen sends a warning you go, "oh well, I had that red warning going all along and it didn't matter, so why do I care?"

I am saying that by pushing a warning where it's not necessary, you diminish the value of any warning.