A few things, if you installed the older 1.2 patch you'll get a message saying the 1.2 patch is already installed when you run this one (it'll also patch very quickly). The new patch will still be applied, you'll see the full screen anti-aliasing option enabled. Even on low it greatly increases image quality.
This new patch brings copies UP TO the same rev as the steam version (including steam demo). These are hot fixes they where able to squeeze into the Steam version, and are now offered to the rest of us without waiting for a 1.3 patch.
If you have an uber rig you can set the 3-D render resolution higher then your display resolution and you now have Super-Sampling Anti-Aliasing :p Probably something to use up the road unless you're running the game on a fast system on a lower res monitor.
There's a mod that greatly reduces the robotic radio-chatter. Check out the mods section. There's another that makes everyone's aim less pinpoint accurate. Firefights now last much longer, and are more forgiving about your poking your head around a corner for a few seconds (though you'll still get hit well enough).
To use a mod, create a folder like @mods then within that folder create another folder called AddOns. Place any .pbo's into the AddOns folder and add -mod=@mods (or whatever name you go with) to your launch shortcut.