I see Magic Lantern has an Auto ETTR module now - has anyone played with that?
Yes, I use it regularly. It has worked very well for me and I'm now happy to use much higher ISO's in my 7D than I was before.
It only works in Manual mode and I frequently forget to turn it off when I'm using AV and the camera gets really confused!
I've posted this before on another thread but it was taken using auto ETTR at 3200 ISO (that was the max I'd allowed it to go to) and would seem to indicate that's there's plenty of head room above that...I used to struggle with 800 ISO.
IMG_9148-Edit.jpg by Mccamli, on Flickr
You can also combine auto ETTR with Dual ISO if that tickles your fancy!