Edmund McMillen is a pretty smart guy, so this Binding of Isaac amiibo tease could either end up being an elaborate AR game, or a pro-level troll. But hey, it's something, and when you consider how much love he (and Nicalis) have given the series up until this point, it could easily happen.
Right now he's teasing it by way of a Twitter poll, and at the time of this writing the results are 70% in favor of "yes." I mean who would say "no," but my guess is that he's looking at total votes to garner interest in providing an initial first run print -- and he has over 10,000 so far.
I wonder how the whole amiibo thing is going to pan out after the Smash line is done. Nintendo is going out with a massive bang with two variants of the last three characters (with slimy exclusive deals), but other than that they're kind of just rehashing the same lines over and over (Pikmin, Zelda, Splatoon).
Edmund McMillen [Twitter]