A crazy amount of new and background information can be found at the Wizards website. Magic: The Gathering promotes going to participating stores to have tracked duels and one of the features they have implemented recently with Return to Ravnica, is having you choose what guild you want to be part of (online). And in doing so, you work with your fellow guildmates to reach achievements and unlock perks (maybe?). Anyways below are some intro emails you would receive for joining the specific guild.
Visit this link to get the background story of what happened on the plane of Ravnica. Very interesting story how, what you'd imagine to be the guild of righteousness (white/blue), Azorius Senate, was the mastermind behind the war.
An interesting paragraph on what is currently happening on Ravnica:
Old guild loyalties that never truly died out began to coalesce and new guildmasters emerged to take the lead, attempting to bring their guilds back to full strength. Rumblings from the hellpit within Rix Maadi sent the Rakdos scampering back to the guildhall to await their demon lord. The merfolk zonots were discovered and a new Simic guild with a new identity, as preservers of Ravnica's natural places, emerged. The Boros began to align under the powerful leadership of the angel Aurelia, who promised that crime would most certainly be punished under the fist of Boros. The Azorius were called on to restore the rule of law and to keep other guilds in check, and Isperia created the lawmages to enforce law through Azorius magic that compels compliance. The Orzhov approached the cynical doubts of the Ravnican citizen with a new tack—the restoration of faith—building ornate cathedrals and gathering places filled with lavish artworks and rituals. Perhaps taking a cue from the Orzhov, the Selesnya engaged in their own peaceful struggle for legitimacy in the wake of the Guildpact's destruction and chose to create beauty among the stark buildings, with places to illuminate the wonders of nature and inspire contemplation—hopefully on the blessings of Mat'selesnya—for all of Ravnica. With all this going on, the Dimir quietly and methodically coalesced into a full-fledged guild again, fueled financially by 'the continued need for guilds to keep an eye on one another and to know every move made by their rivals.
Once again from this article.
An exciting beginning quote to this article:
"Return to Ravnica previews begin next week..."
Can't wait for new information!