Trainz 12 includes a large number of animated switches. Well, as far as I know officially, they do not SHOW the animation for changing state, they just show which direction they are in visually.
Most work by combining a "building" object composed of fixed track, with placed invisible track and a specially designed junction.
Trainz 12 notably includes the HOTT animated turnouts which are quite good to use. However, because they act as a solid object, they cannot be used on gradients. (Though, I personally prefer to never build turnouts on gradients because it's annoying trying to get the track to line up...)