I'm pretty excited for it, but I'm a big MGS fan, so take that as you will.
I was originally optimistic with Kiefer Sutherland being cast as Big Boss. Just a little gruffness and tone down a little and it would make a decent pass and fit. When I watched the trailer and heard he was just using his normal voice, I was a little bummed out. However, this being 1984, both Snakes would be 12, and potentially David Hayter could be a background character or even a young snake (though how he could do a 12 year old's voice is beyond me).
The setup for the plot is really intriguing and I am genuinely interested in the descent of Big Boss from hero to "terrorist", not to mention the open world and dynamic environments get me super excited too. :3