I'd say Sony's a great developer and publisher, and honestly always have been (Skyblazer <3 <3). I'll admit to not being entirely happy with their output this gen (wtf happened to Japan Studio?! Dude Raider, that hokey French non-game and all those wish-they-were-Halo FPS can diaf!) but there's really no denying their progressive and innovative history in terms of games. Stuff like Parappa the Rapper, Carnage Heart or Tail of the Sun, I couldn't have really seen anyone else take the chance on back in the day (certainly not Nintendo or Sega). And honestly, gaming is better off for it.
They do seem incapable of developing a "ground up" mega-hit franchise though for some reason, especially now. Even the success of something like Gran Turismo is entirely predicated on real life licenses... does anyone think the GT games would've sold 9-15m each if they used purely fantasy cars, manufacturers and courses? The closest I think they've legitimately gotten to a home grown ground up megahit is probably Crash Bandicoot, and unfortunately there they didn't own the IP (or the developer, at the time).
