For PvE, the story must have its intensity and allow the players to make their choice when doing quests and their choices will lead different consequences (like fable). In short, the story should be competitive to any single player RPG 's story (like baldur's gate series or Planescape: Torment) and the gameplay allows the replayability. For example, it will be good if choices are implement in quest that what you decide when doing a quest will give different outcome, leading you towards good/evil not reward/no reward consequences. Moreover, the background music must improve such that when one enters into combat, the music should change into a face paced music to bring out the intensity of the combat.
As for extra job, i prefer an additional ninja/assassin where he/she can go into stealth and do backstab damage. I love the excitement when i able to finish a character in one hit kill..

However, there must be moderation made to the backstab damage as it would lead to imbalance of the game
It would be good too if there is PvP match like castle siege where a faction must play defend while the other is attacking..considering both sides (defending and attacking) providing equal amount of fun..moreover, the number of maps for PvP seems too little considerate this game lies more toward PvP..
For me, MMORPG players like large scale PvP match..the larger the scale of PvP match..the better it is..it would be amazing if arenanet can design a large war map between two or more factions (i am assuming if there is additional factions added in the expansion), then, these factions will fight a war between each other in a race to capture strategic points and defend it for some amount of time in order to gain that strategic points (i am speaking of this referring to Warhammer 40k : Dawn of War), whoever with more amount of strategic points will be able to gain favour from gods (now i am speaking of this based on guild wars), for those who gain favour from gods, they can gain access to additional map areas (which is already done in original guild wars but the amount of additional map areas must be increased as well). Hence, the PvP match is no longer just between two factions every time, it is involving a large scale war, tactics and it is a race as well..
The rewarding system in the PvP match must be enhanced as well, not only ranking, factions, celestial sigil, etc, etc..i think the idea of unlocking a new map area as a reward for gaining god's favour is cool but after the players gain fissure armor, weapons, etc, etc..there is no point to continue the game anymore except monitoring their guild and making sure the guild is in high rank. The rewarding system must be enhanced in order to bring back the high level players to be always active in PvP match, increase the competitiveness of the PvP match, and most important of all is the sense of satisfaction when one wins the match..
Moreover, it would be good too if Anet includes other activities than just PvP matches and farming in the game. MMORPG is just not a game, for some ppl, it is their whole life.
I am speaking of this based on my idea. I hope that u guys will forgive me because my english is not good.
