Yea CC is very important in GW and comes in lots of forms, such as knockdowns, blind, weakness, slower movement / attack rate, and also not to forget protection type roles with damage reduction.
One very unique feature with the first game was how equally important protection and damage mitigation was to simply pushing red bars up. If you tried to play many of the elite areas on hard mode with nothing but heals for support, you would get squished in no time.
Most other games only revolve around 'red bar up' healing mechanics, with no where near as much protection and shutdown roles as GW has.
In fact one of the best things I loved about the first game was that my elementalist could play the roles of damage, tank, healer, protection or shutdown. Due to how underwhelming elemental damage was in hard mode, I turned to playing protection and healing roles and thoroughly enjoyed being able to swap my build to whatever was needed in the group. Monks were always so rare to find, even while I was in an active end game / HM guild I would often play an E/Rt restoration healer, or E/Mo protter so that the group was filled and ready to play a lot quicker than having to wait for a healer.
It was also surprising that as time went by, Necromancers and Elementalists became the primary choice for healer and protection roles over monks due to their vastly higher energy pools, while player monks were better off using the smiting elite ray of judgement as it did far higher damage than elemental nukes due to being armor ignoring.
GW1 was a rather big balancing failure - too many classes, skills, and cross profession combinations made it far more difficult to keep everything balanced compared to other games. This is why I believe that GW2 is having far fewer skills, no more secondary professions, and 5 locked skills based on weapon choice because this is far easier to balance than GW1 was.
Just have a look through these Elementalist traits for GW2:
http://wiki.guildwars2.com/wiki/List_of_elementalist_traits
Fire - Full AoE Nukage and Burning
Air - High Single target spike damage, speed, plus CCs in the forms of knockdowns and conditions
Earth - Tanking, CC and condition focused and damage
Water - Healing, buffing, survivability and damage
I would assume that similarly to the first game, earth and water would do less damage than air + fire, each role being situational and preferable based on what area you are playing and what your group requires.
Another great thing about GW / GW2 is that you can respec anytime with no cost or cooldown attached to respeccing like most other games have. If you somehow build your character wrong, or want to play a different way, you can do that by pressing a few buttons, no need to start over again or make a new character, one character of each profession will always be able to play any role that profession offers, you dont need to have any specific gear either.