To be honest, I'm somewhat sad to see this go as well. It all comes down to management and sacrifice. Playing an Monk in the original Guild Wars, nothing was more exciting then being strained to switch to your high mana set (at the cost of mana regeneration) and having your team just barely survive the encounter. Swapping weapon sets to hide your mana from Energy Burn mesmers, keeping everyone's positioning in mind, knowing who to prot (much more effective then heal), and managing a skill bar of 8 that not only had to be able to deal with the wide variety of enemy compositions while maintaining survivability, mana and cooldown management, and positioning was the majority of the fun playing a support class.
I fully expect GW2 to be a great game, but think they are missing some key things that made the original great. Here's to hoping they bring back actual GvG