As 340WM said, the new ones are designated VX. The old ones are Vari X. Only certain models have side parallax adjustment. The 3.5-10 doesn't have it as far as I know. As he also mentioned, the elevation and windage adjustments can be made by hand on the new scope. The old version required a coin or screwdriver.

I've got a VX III 3.5-10x40 on order myself. I haven't owned a Leupold in two or three years now, but I'm excited about these new ones. I hope they live up to all the hype.