We gave Risen 2 high accolades in our review, but did note somewhat concerning performance issues. A new patch has been released which we're told addresses them, and also a bunch of other interesting elements.
Combat has been tweaked significantly. For one, you can now dodge during combat. Not to worry: it's not a be all-end all to avoiding damage -- from what we hear it takes real timing and skill. You can also block most monster attacks, which is an off putting change. When a monster lunges at you with its claws or what have you, it's not remotely realistic to be able to simply put up your sword and expect things to be fine. With a shield, sure, but far as we know there are no shields in the game. Monsters are now more intelligent in combat now, however, so that should make up for it some.
Besides that you get fixes for SLI and 7.1 sound, a limitation on auto saves to 10, and various other fixes and tweaks.
Hit the source for the full list if you want it, and boot Steam to download the patch now.