1600x900 is just fine, not sure why are people so upset...if they wanted it to be full 1920x1080 with less effects they would've made it that way, but that would be just silly.
Still, it's interesting to see that it's exactly the same resolution that EDGE article mentioned, and I can see lot of future titles running at it (while we're at it, I'm sure that eventually PS4 titles will drop to that or similar for more gfx bling-bling).
Anyway, 900p or 1080p doesn't matter at the end, Ryse is doing absolutely nothing for me, visually or gameplay wise.