Valve, most developers have no qualms about developing for PlayStation 3. Sure, it's still far more "tempting" to work on the 360's accessible architecture, but most recent releases appear to have shaken PS3's earlier substandard multiplatform performance.
Most. Bayonetta developer, Platinum Games, recently admitted on its blog that it was not developing the PS3 version; instead, it handed off PS3 porting to Sega. Platinum Games' CEO Tatsuya Minami wrote on the company's official blog that Platinum would be "overseeing the progress to ensure that the PS3 version would be the best it could be." However, instead of saying both versions will run identically, he simply advises PS3 owners to "[play] the game for yourself and [come] to your own conclusions."
PlayStation commenters weren't too kind to Minami's admission, saying, "Platinum Games is trying to shift the blame to Sega" for what gamers fear will be a substandard port. History certainly gives their worries credence, but we'll find out for sure later this week at Tokyo Game Show.