See hq.dragonage.com for all of your multiplayer data - loadouts, core stats, defenses, etc.
This page needs a major cleanup - will be getting it all together soon-ish!
Multiplayer was announced for Dragon Age: Inquisition a few days before PAX Prime. There will be hands-on demos at PAX for people to try it out!
More information is coming out at PAX - I'll merge into here after PAX is over. See the PAX Prime coverage page for additional info.
From Scylla Costa, Dragon Age: Inquisition producer.
We are very happy and excited to announce that Dragon Age: Inquisition will have a multiplayer mode! Separate from the massive single-player campaign, Dragon Age multiplayer is a four-player co-op dungeon-crawling adventure is set in the world of Thedas during the Inquisition. So, invite your friends and be ready to play your role in this tactical and action-paced game mode. Dragon Age multiplayer will have a deep crafting system, many different types of potions, twelve different characters and, of course, a variety of strong and challenging foes.
If you are going to attend PAX Prime 2014 in Seattle (August 29-September 1), drop by the Microsoft booth (412, 422, 432) and play Dragon Age: Inquisition multiplayer with support from our developers. If you want to know even more about this mode, you can also attend one of our panels at the PAX BioWare Base. We have also prepared a quick multiplayer FAQ that you can access here [link added].
Gather your friends before venturing forth!
Articles, previews, and first impressions:
Destructoid: BioWare: 'We will support Dragon Age: Inquisition's multiplayer far beyond Mass Effect 3'
Destructoid: I enjoyed Dragon Age: Inquisition's multiplayer a lot more than I thought I would
EA: Dragon Age: Inquisition Unveils Cooperative Multiplayer
Game Informer: Dragon Age: Inquisition Will Have Multiplayer
Game Informer: Dragon Age: Inquisition A Step-By-Step Guide To Multiplayer
Game Informer: Dragon Age: Inquisition Five Incorrect Assumptions About Multiplayer
Game Informer: Dragon Age: Inquisition Exclusive Multiplayer Menu Screens
Gaming Trend: Why Dragon Age: Inquisition is Bioware’s most ambitious and dangerous game yet
GameSpot: Dragon Age: Inquisition Has Multiplayer; First Details Revealed
GameSpot: Check Out Dragon Age: Inquisition Multiplayer Gameplay Footage
GameSpot [Video]: Why Dragon Age: Inquisition's Multiplayer Isn't Like Mass Effect 3
IGN: Dragon Age: Inquisition's Co-op Multiplayer Is All About Loot
IGN [Video]: Everything to Know About Dragon Age Inquisition's Co-op Multiplayer
Kotaku: Co-Op Multiplayer Coming to Dragon Age: Inquisition
Origin: Five things you need to know about Dragon Age: Inquisition’s Multiplayer
Bioware Multiplayer FAQ: http://www.dragonage.com/#!/en_US/news/multiplayer-faq
gamermd83 put an informational video out on it..
There is a Multiplayer group on the Bioware forums - sign up now to set up in November
Multiplayer IRC channel and instructions