MotorStorm Apocalypsehas been updated with a mode editor, the ability to share custom vehicles designs, further controller options with new PlayStation Move and racing wheel support and enhancements to online play based on user feedback. It's free, because who needs money in the apocalyptic future when there are races to be had?
To elaborate, the mode editor lets you tweak the rules of MotorStorm for on- and offline use. As for the vehicle customization, you can upload your designs to the game's official site, browse through community creations, and download them right then and there to Apocalypse. Slick.
Give the PlayStation Blog a quick browse to see which specific racing wheels are functional as well as the exact changes that have been made to online multiplayer.