Yeah it's pretty hard to tell at this point but my guess is that it will be like the mk45 1/4. Having both the button and pull down. This is, from what I have heard, supposed to be the top of the line best iron man figure. A couple of the designers at hot toys have the mk6 as their favorite suit so I expect it to be the best figure yet at 1/6. Just my guess though.
From the pics it looks like they have the button but also the gold thigh section extends down to increase the range of motion.
With the shoulders I think the 1/4 45 is the gold standard as well. With ball joint on the pads with a secondary gap cover piece under that. But whatever they do I expect this figure to be the best figure yet, engineering wise. Usually how they do it. And as I said this is an armor a lot of the hot toys folks really like.