Trine collective, Steam was busy updating the PC version of the game with free content. According to the Steam news page, Trine received a free DLC level named "Path to New Dawn" as a post-completion bonus this past Sunday. Additionally, a handful of minor updates were made to the game itself, ranging from new information on "experience and secrets in the inventory menu" to fixing a "respawn bug in [the] Iron Forge level (in co-op) near the first gate."
Unfortunately, it appears that the release of this new content in the PS3 version isn't a sure thing. "At the moment we're not sure if the free DLC is going to get released on PSN," developer Frozenbyte told Joystiq. "It's not in our direct control but we'd love to get it released and are trying to make that happen -- but at this point it's hard to say how it will play out. Same goes for the price as well." When we pushed for info about any additional DLC in the pipeline, we were told, "There's no immediate plans on any platform. That said, if you have completed Trine on your PC, then I'd suggest completing this extra level as well, collecting all the 10 purple potions ..." You should probably do that if you're in a position to go potion-hunting.