"Guild Wars 2 does look very fun and appealing even if I’m still not holding my breath for a revolution in the MMORPG industry regardless of how much ArenaNet claim it be so (I may be wrong though)." Gordon, We Fly Spitfires
There is everything wrong with this sentence. Luckily Gordon disclaims his insufficient knowledge about GW2 in his pots, so I am not blaming him. But there is this one big misunderstand which needs to be cleared and gone.
There is no revolution in GW2, it's all evolution.
Every single part of this game is carefully crafted and fits into another parts of the game seamlessly but there is no revolution in there.
Hearts are evolution of classic quests hubs where instead of having 5 quests asking you to kill something, collect something, interact with something etc. you have all those in one pack and you just choose what you consider most fun, and do that. If you love burning frogs with flamethrower, you can complete a Hearth this way and completely ignore other objectives.
Dynamic Events are evolution of Rift's Rifts (been there) and Warhammer Online's Public Quests (which I haven't played but I get a lot of info from my friend who spent a helluva time in War). In Rift there are events appearing in predefined positions, spewing mobs and you either win or lose. Both have consequences, but each rift is a self-contained event. In Warhammer Online you had public quests where everyone could just come and start doing what other people were doing without invites and get rewarded. In GW2 we have events appearing in predefined positions but each event has multiple win and lose states and trigger other events in the chain. For example frog village gets attacked by thieves, if you protect the village enemies get more desperate and hungry and send a raid to the village. But if you fail you now have to go to enemy's village and get the stolen food back.
Both Hearths and Dynamic event are out there in the world and interact with each other. Many times I have completed a Hearth by doing some random Dynamic Event.
WvWvW(World vs World vs World) is evolution of Warhammer Online and Dark Age of Camelot siege modes. There is frankly not much I can tell about WvW without making things up, as I haven't been there at all, not even during Beta Weekends. Same goes for Structured PvP. I am not gonna dabble into regions I am not good in.
Exploration may be on the other hand considered by some as revolutionary, but it actually isn't, it's just a smart mix of game mechanics. There is exploration of map to get 100 competition, but then there are chests with treasure hidden everywhere in the world, not marked on map at all and usually requiring some devilish jumping puzzle to be crossed to get to it. Then we have exploration based crafting, where you have a lots of materials but almost no recipes and you just try to mix what makes sense, and thus create new recipes. Sometimes the combos are quite crazy so there is a big chance you will have some recipes nobody else does for some time. Been done in other games tho, but not in such a complete and nicely fleshed out package.
So as you can see, there is not much revolution in GW2. There may be some minor features which may be considerer revolutionary by some, but you can say this about any game. Do no thrive for revolutions, they are dirty and noisy and lots of people get left out (or in RL killed).