Well, what is left to keep players interested in AoC that would keep guilds alive and well? I see three things: Raids, PvP, and RP. RP community is dealing with its own share of the pie right now. PvP is getting some attention, but I don't care enough for PvP to pay attention to it. I hear new minigame maps would be nice, but I don't know that it would add any much more lasting appeal than the current maps do You're basically killing people against a pretty backdrop, and if the backdrop changes, the killing people generally doesn't change, except to make it easier for ranged in some cases. And as for Raids, they are getting T5. Of these things that people would join a guild for, raiding requires most resources from Funcom in order to churn out. But there are guilds that exist solely for the purpose of raiding, and maybe some 6-mans. Because these things are time-consuming, and keep people in the game. I did the solo main story for the Dragon's Spine in a day. One day, spent in a beautiful map that ultimately didn't have much to hold me there except a few nice set pieces for RP. That's not a very promising outlook for content creators. Haven't touched the 6-mans yet, but they're spent outside of the big map.
So what can Funcom do for AoC? With guilds as a small part of the bigger issue? Class balancing is upcoming and welcome. Beyond that, maybe the crafting revamp, which will probably never see the light of day. And then, most crucial for the Raiding guilds, is progression and more raids and 6-mans. For guilds to survive, the content they rely on needs to survive. There's really not much that's going to happen right now for players unless they make T2 free to play to give potential T3-T4 raiders a chance to see what lies beyond the two T1 instances we see right now.
So while RP guilds can sort themselves out in-game or by website-to-website dealings, and PvP can do their thing, Raid guilds are AoC's lifeline and what keeps the money flowing. Since that's what people actually NEED to subscribe in order to access. Making things as comfortable for them as possible so they don't break up and cause subscribers to leave is in the interests of Funcom. Raid signups sounds like a good idea that may eventually lead to more raid guilds actually forming. At least in theory. I'm thinking this won't work without a lot of help from existing successful T3 and T4 raiders to get first-time T3 and T4 raiders into the loop.