The appeal of the game, much moreso than other genres, was that it allowed for an expression of creativity within the gamespace. And not just on a superficial level, but on a competitive gameplay level. Working within a seemingly complicated framework of skills, attribute levels, professions, and group interactions, this game allowed me to explore just how creative I could be in coming up with character or team builds that could meet the PvE and PvP challenges in the game.
This kept me interested in the game for over two years, and I thank the developers who came up with the game designs that were interesting enough to keep my attention for that time. Here are a few parting ideas/suggestions that I hope can still make it into the design cycle for GW2:
1) Passive abilities. Not everyone enjoys micromanaging abilities that require constant attention. Enchantments provide great versatility for short durations, but the opposite mechanic was never really explored in the game. Using attribute levels to boost profession-specific passive abilities was implemented at a very basic level with primary attributes, but could have been explored so much more than that.
2) Dungeon or instance design. Create a tool to allow USERS to develop their own instance or dungeons that other USERS could compete in. This would blend both PvE and PvP realms: dungeon/instance designers would create maps filled with groups of PvE monsters using PvE skills, but would try to counter groups of real-life people who would attempt to defeat the challenge. You could immerse this within the PvE world fairly easily by having NPCs which would "sell" land and mercenaries to guard your land. You'd therefore have controlled map geography and allow for players to come up with challenges. You can even tie it into the economy by making incentives for good dungeon designers and/or monetary penalties for bad ones.
EDIT: This one has generated a few responses and I needed to clarify. This was done with a reply, but I am copying + pasting here in OP.
"This one was by far my most radical suggestion. I still think it's implementable. How's this as a variant that might be better suited to GW:
A guild alliance of some suitable stature (don't know what they would use to determine this - size, or money, or some measure of competitiveness) can purchase, in addition to a guild hall, a "guild grounds". They can hire AI mercenaries to guard the guild grounds, and they can CREATE groups of AI mercenaries with whatever skillsets/attributes/compositions that they desire. There could be some sort of resource allocation system involved: high ranked guilds might have high amounts of resources while low ranked guilds would have less. Defeating the "guild grounds" would be a mini-game prerequisite to challenging a guild to some contest. Different guild ranks could be used for different benefits (GvG rank might increase the mob level, some other rankings might increase the number of AI or how many elite skills are allowed, etc)
This provides another avenue of creativity: guild members (ie - players) will actively create and test their own groups of AI to provide sufficient challenge so as to gain some sort of benefit when another guild challenges them and does not succeed in overtaking the "guild grounds" mission. (Perhaps some sort of guild fame rank)"
3) Titles. Eliminate reputation-based titles altogether. No one wants to grind faction rank, or sunspear rank, or asuran rank. You took a surprising turn in EotN by adding MORE grind. I'm all for titles: but they should be skill or accomplishment limited. You can keep silly ones like drunkard and sweet tooth if you want though

4) In-game economy. You've got to do better than what was offered in GW1. I remember for the longest time there wasn't even a TRADE channel!! That was a tiny step in the right direction, but no one wants to sit around and spam to sell things. Take some cues from games like WoW (auction house) or EVE and incorporate things that will make the economy more interesting.
5) Items. Although I appreciate making items not the focus of PvE gameplay (like WoW does), you really devalue items too much by having so many "perfect" unique items as well as the ability to perfectly mod everything. It ended up hurting the economy a great deal.
6) World interaction. It's already been announced that there are some interesting things in the works for new world interaction mechanisms. GW1 was sorely lacking in these.
That's all. Good luck with GW2, and I hope you don't follow the path that many developers have and try to "streamline" GW2 (ie - dumb down and make LESS interesting) for the masses. Looking forward to 2009!
--uby
PS - no, you can't have my stuff.
