you can also get it by going to the Unreal II folder and click the "Check for Updates" icon
Does it help the framerates any? I uninstalled U2 quite some time ago after beating it, unless the patch gives a big increase in performance I probably won't reinstall it..
"PS 3.0 utilizes a wide range of optimizations, from 64-bit frame-buffer blending to looping and dynamic conditionals for rendering multiple light interactions in a single pass without requiring a combinatorical explosion of precompiled shaders."
-Tim Sweeney
Yes it does increase framerates,but more importantly it makes the game completely playable,even with a lot of bad guys on the screen it does not slow down nearly as much now!