In terms of TES:O we already know we have three factions of three races, and that we have faction warfare... but we know nothing yet about guild/clans and their role in the game. Many people myself included are concerned about being arbitrarily limited to only playing cooperatively with the races in your own faction.
So do we want to see the ARAC option, not just for guilds, but for the game in general? What does this mean? It means no language barriers, no enforced segregation, ability to be in parties and quest with non-faction allies, and the ability to explore each other's provinces freely.
I think the answer is obvious, but what are the implications? Does this work from a lore perspective? Does this work with what we currently know about how the end-game PvP works? Will this cause more problems than it solves (Like in Darkfall where everyone totally ignored racial motivations and every guild was an ARAC guild for convenience of recruitment.)