Hardcore players play everything and anything of merit. Not just M and AO titles like the know nothing prepubescents on Xbox Live would have you believe. The key word is merit so, that also means that most hardcore players aren't going to have many games that are "M for the sake of being M" games in the roster. I don't think you neccesarily have to OWN everything, and anything to be hardcore, but you'll be open to actually play it. This gen I've been PC, and Wii so far. I'll probably get the 360 next, and the ps3 is last on my agenda.
But it doesn't mean I'm not going to ever play those. I play 360 at a friends whenever I visit. I've played the PS3 a few times at stores, But outside of UT3 which I'm buying for the computer anyway, not much really wows me. But I'll admit it has a few nice things lined up. I think the cost issue with the PS3 is less a matter of it being pricey, and more a matter of "What else can I do with $600" $2000-$4000 if you're throwing an HDTV, and Accessories into the equation. $4000 builds me a hardcore rig, and one of the other consoles to hook up to the bangin' HD monitor it came with
Going back to Hardcore though, I think Hardcore types need to crackdown on the aforementioned preteen poseurs. They're giving us a bad image! Abusing 13375p34k (For crying out loud you're only supposed to SPELL words in leet not pronounce them in leet!) overusing words like noob, calling a new player a hack when he cleanly beats them calling his leetness into question.
And for God's sake where are their parents? Just because you're playing over the internet doesn't mean you don't have to be polite anymore you little swear word.
And markatsiu is right man. DX10 with a Geforce 8800 GTX on a dual or quadcore system w 2GB RAM is going to blow away anything the PS3/360 can do. That's not to take away from those systems, but if you have to be cutting edge all of the time a DIY PC is where it's at graphically. And E3 showed a pretty big commitment to the PC IMHO. Lots of multiplatform stuff also coming to PC.