Yeah the DLC codes work now. I played through the first episode last night.
Spoiler:It was a little underwhelming, it's actually just one of the press demos they showed before the game was released. Really short too. I shouldn't complain though - I did get it for free. Hopefully the next episodes will be longer (an hour or two at least).
I keep hearing these reports of bugs and honestly I must be one of the lucky ones. The first time I played through the game (on a 80 GB PS3) I didn't experience a single issue. No weird graphics or audio hiccups and certainly no crashes. My second playthrough is currently on a different PS3 (a 20 GB one) and I'm noticing a couple of odd things. Longer than normal load times. An audio hiccup here and there. I wonder if some of these bugs are caused by differences in hardware?