We have recently had some more details emerge on the new Cataclysm guild advancement system.
For those of you who may have missed it, Cataclysm will be introducing a new guild advancement system that provides guild members with added "perks" based on the guild's level.
How is guild experience gained?
Guild experience can be earned in any of four ways:
1. Completing quests / daily quests that reward experience
2. Killing any dungeon / raid boss with a guild group/raid
3. Winning a rated battleground with a guild group/raid
4. Earning a guild achievement (these are nice, fat chunks of experience so they feel great when you get em)
A guild group/raid is 4/5, 8/10, 12/15 or 20/25 members of the group/raid being guild members.
There is a daily cap in place for guild XP in order to keep things balanced between large/small guilds. We made the cap high enough that in most cases, you will not even notice it. The cap is visible on the guild XP bar as the blue color. You can also get more details by hovering over the xp bar and reading the tooltip.
What perks can we get? There are lots of good things including increased XP gains, increased mount speed, mass resurrection, increased reputation gains and more. See the list of the guild perks available
There is also guild rewards available from your guild vendor. These include rare mounts, vanity items, recipes, rare reagents and guild heirloom gear. They are unlocked when the guild completes selected guild achievements. Be aware that you will need to work on your "guild reputation" in order to take advantage of these guild rewards. This is a mechanism designed to reward longer term guild members before newer members.
Any quest that rewards experience to you will also reward guild experience. The amount of guild reputation earned is based on the amount of guild experience rewarded. Note that daily quests will also reward guild experience.
Guild reputation will also give you access to guild rewards (including guild heirloom items):
Guild rewards have 3 requirements that must be be met before you can use them. First and foremost, they must be unlocked via a guild achievement. Let's just say, that for example, you need to complete the new guild achievement "We are Legendary" in order to unlock the Dark Phoenix. That achievement requires the guild to gain access to all 6 legendary weapons currently available in the game. (note that all guild achievements start on Cataclysm launch, so anything you have now will not matter, it must be done with your guild after launch)
So, let's say that your guild get's this achievement and thereby unlocks the Dark Phoenix on the guild vendor. At this point anyone in the guild can see the item on the vendor, but they will need a specific amount of guild faction to be able to purchase it. In this case, let's say exalted. Now, once you have the guild faction, you can purchase the item for its gold price.
The Guild UI has been redesigned to handle all of this. Check out a recent news article
by the WorldOfRaids.com which covers the UI changes in more detail.