I also noted the inclusion of flights of birds and for some reason this really appeals. I recall watching a documentary dealing with Roman times and as some of the CGI camera views panned across Rome, flocks of birds passed in the opposite direction just below. This 'simple' feature gave an almost 3D sense of height as they swept majestically along below us and I always hoped it could be included some day in our flight sims. They tried it in Wings of Valor (I think) but it was poorly done.
From a flying perspective, maybe bird strikes could upset one's landing approach just to further complicate matters . . .