5 years since I started this thread and having just seen an email with details of the 2016 promotion, I think McD's have come close to actually cracking this.
This year they are only rotating 3 different burgers, with each burger on promo for 2 weeks instead of trying to have 4 or 5 different ones for a week only.
This cuts down the previous complaint of mine that there wasn't enough differentiation between the burgers. In some respects there still isn't, cheese and bacon still dominate but at least you can almost make a case that the burgers do relate to the region a bit better.
The other thing is they are all double burger 'stacks' where I think before all were just singles.
The first two weeks is a Tennessee BBQ stack, which has cheese, bacon and a BBQ sauce. Nothing groundbreaking admittedly, but at least Tennessee is a region associated with BBQ flavours.
The second burger is the New York Stack, the key element here is that it is served in a bagel, which is a typical NYC item. Again, the burger and toppings are fairly generic, but at least serving it in a bagel does give it some association with New York.
The third and final burger is a Tex Mex stack, this includes off the top my head a spicy jalapeņo cheese amongst other things. Somewhat more Tex Mex than the year they had Pepperoni as a Texas theme, because I can't for the life of me see why Pepperoni is connected especially to Texas.
I believe for the full 6 weeks a Buffalo Chicken Burger will be available, which sounds pretty good. For once, I can't really moan about this promo, if you read back through the thread it has been something that has annoyed me year after year ( within context)