Todd,
I've seen the 3-D exits while driving in Jax. Not all, but some, do have this feature. One I can think of off the top of my head is traveling I-95 N and then on to I-10, that exit has the 3-D. Also, the I-295 / I-95 interchange has them as well.
[Edit]
I take that back....I looked today driving I-295 S then continuing on 9A and there was no 3-D preview. I believe it does show up if you go on I-95.