a) With all the rifle suggetions, I was suprised to see that the sig55X series wasn't mentioned. I think it deserves a spot on that whishlist . It's widely used in many different armies and special forces.
b) I'd also like to see realistic Acog sights. Acogs are designed to be used with both eyes open, giving the user the unique ability to have his normal field of view when not focusing on the reticle. This is also called the Bindon aiming concept: http://en.wikipedia.org/wiki/Advance...tical_Gunsight.
In Arma 2 the Acog is simulated like a scope-sight that requires you to close one eye and align the other exactly with the target and therefore loosing your peripheral view. The new render-to-texture feature could be used to zoom in the sight area.
Apart from this the sight in Arma takes up 80% of the screen (probably to compensate for the loss of peripheral view) which could be realistic for a scope but not for an acog. It takes up smaller part of your view.
My suggestion would be to slightly blur the outside of the sight when one aims down the sight (the eye is focusing on the reticle) and slightly blurring the inside when the surrounding is scanned.
The result could look a bit like this althoug it wouldn't zoom in the whole screen: http://www.youtube.com/watch?v=27AlHzgTcN8
If zooming in the sight with render-to-texture with the outside staying unzoomed should prove to be too complicated to be incorporated, I and likely others would already be happy with the way it's done in the video.