I've been reading through old posts and came across this about the "gift":
All preorders will get it, and the earlier the order, the more you will get.
Now, in the past I always interpreted that to mean that all preorders get some gift, but that earlier orders get either a better gift or more gifts (but each one different). But what if it means the SAME gift, but the difference only being in how MANY of that SAME gift you get?
Wouldn't this have some effect on any guesses? If we take the most extreme, but somewhat serious guess - that it could be an extra TB, I think this interpretation would take an already unlikely gift into the range of "guaranteed not to happen"! I mean, it would be one thing to do that for the very earliest orders (unlikely since 10k or more ordered in two days!), but imagine doing that for EVERY pre-order and then doing 2 for those even earlier and, who knows, 3, 4 whatever, as you move to the front of the line! So, if it is a matter of more of the same for a gift, it can't be a TB.
Another suggestion was a nano-stand. I wouldn't mind that at all, but how many nano-stands would one want - especially if they already ordered two (one of each size)? So, possible, but this also becomes less likely unless it is limited to two (very early get two) and, if you already paid for one or two, they reimburse you.
Then we had the possibility of a nice case for the device. Again, cool, but of limited benefit to get multiples of them other than having an extra when one eventually wears out.
Anyway, it may not be the way I suggest - it is just one possible interpretation. But if it is correct, maybe others can use this info to offer appropriate possibilities. Remember, we already know it is a t-shirt or coffee cup (there was a third item they said it wasn't, but I don't recall what it was).
Also consider that Juli at MacRumors said it was described on the box top - so apparently isn't shipped with it. That could create another possibility - that people are actually give a choice of gifts - or how many - and order it.