The issue with the 7D was the dual Digic processors, with the 5D3 having a single processor, I have high hopes
Then think about sponsoring Alex' ml development if you can afford a 5d3...
This was certainly one of the upgrades I was hoping for as well (why wouldn't canon do this - it must be a fairly straight forward change?).
Even if sounding a bit repetitive :-p ... magic lantern does this, too, it even calculates how many brackets you need on the fly - so shoot 10 or more pictures with 0,5 ev steps for exposure fusion, no problem there.
It is sad that manufacturers have to resort to these firmware annoyances to sell their stuff, but for once Nikon isn't any better - e.g. the d7000 only does max. 2ev 3x bracketing which too little in many situations, too.