The Guild Wars 2 team is asking players to begin by choosing three priorities from each area of gameplay and listing them in a response to the initial post. For example, a player's PvE priorities might be ascended items, world events, and roleplaying. ArenaNet will then take the top item in each section and start a separate thread in which players and the team will share opinions, brainstorm, and converse.
Our own Anatoli Ingram tackled the initial announcement in this week's Flameseeker Chronicles. As for this first round of feedback, players have "a couple" of days to add their thoughts before ArenaNet compiles the list.
[Thanks to Mikey Moo for the tip!]