Right now, a lot of people are voting for both kinds. For example, my preference is for windows keys, but I'm voting for Esc keys also, because I am willing to get either kind we produce. But if we were to produce both kinds, I would only be buying Windows keys. So even if Esc keys get past the 25 order minimum in the voting, that doesn't mean we'll have 25 buyers if we produce both.
Not only that, but if we really did have at least 25 buyers for each kind of key, we'd probably be better off producing one kind of key because they start getting a lot cheaper if we produce lots of one kind vs. two different kinds. Really, unless we start getting hundreds of orders, it probably won't be practical to produce two different sizes of keys.
Again, I'll know more when 7bit gets back, because he's already had lots of communication with Signature. For all I know, producing different sized keys doesn't require any additional machining so we could produce both sizes at no additional cost. Or maybe it's cost prohibitive to produce custom art keys with less than 100 orders. I just don't know.