I've been playing Killzone 3 online which might I add, is fucking amazing, I love being an Infiltrator since I can stealth kill tons of people without being seen (Once you get it level 3 you don't come out of disguise when melee killing... lol) and you have to be stood pretty close for them to see through you too, so it's pretty decent, especially with the 50% extra run speed and infinite stamina, although I can feel that getting nerfed somewhere down the line.
I've also been playing The Saboteur, it's sort of like Grand Theft Auto meets Assassins Creed but set in WW2 Nazi occupied France, it's actually pretty cool, and the story has been interesting so far.
I think once I'm finished the The Saboteur (Apparently I'm 45% in after 11 hours, but some of that was messing around) I'll run through the Killzone 3 campaign, maybe wear out it's multiplayer a little more, and then move onto Mass Effect 2 and Nier (I'd like recommendations here, which should I play first?), hopefully by the time I've finished all this I'll FINALLY be able to play Darksiders (Had it for ages but not even put it in the PS3 yet), and maybe even LittleBigPlanet 2 (Bought it on release day, it's still sat with the wrapper on it, with a line of dust on the top... lol)