Thanks guys, that really cleared things up a bit.
I really, really hope those exploration modes are hard as hell, since that seems to the niche for the hardcore players. Still I honestly don't think, that the big-scale events will be very hard for the individual as long as some good players take care of key mechanics (like ArenaNet did in the demos).
I play WoW and I've never managed to do heroic modes, because you have to grind normal modes and now you even have to grind LFR for at least the 4-set bonus, so people allow you in normals. Redundant grind I despise and that's why I'm really looking forward to GW2.