For those of you who group, raid, and otherwise hang out with your guild, here's some pretty cool news for you. Tigole has said over on the Beta Suggestion Forms that the dev team is very interested in the idea of guild achievements, and does plan to visit them in the future.
It's a small tidbit, but it's enough to get the old wheels turning. The most obvious achievements will probably revolve around dungeons and raids. Get X% of your guild through a certain dungeon, perhaps, or finish the dungeon in an all-guild group. We might also see accomplishments for getting a certain amount of guild members their tier sets or legendary weapons.
Of course, at the same time, there's some questions and problems to deal with as well: How do you cater to more casual guilds that wouldn't be interested in raid-type achievements? Do you cater to them at all? How do you account for members who got their gear and recipes in another guild? Does that gear count for any gear-related achievements for their new home server? And what about guild alliances? If five or six guilds band together regularly to take down bosses, who gets their achievements? Do all guilds who had a member in the raid get it, or do only guilds had a certain proportion of members in the raid get it? Will they finally implement a way to officially track guild alliances to solve that problem?
And while we're at it, why not add more guild functionality, like, say, guild housing? Yeah, I know. I can dream. But regardless, it's nice to see Blizzard focusing a bit more on the guild. While they've built an incredibly good looking and accessible game, sometimes they seem to have a pretty large blind spot when it comes to facilitating the social side of their game. More features and functionalities for guilds are one step in fixing that, and I hope we see this trend expands in the coming patches and expansions after Wrath.