User blog comment:Gh0stCrawler/Skyrim DLC Idea/@comment-4014071-20120814020843/@comment-3492791-20120816092109

Hey it's me! That anon! I remembered I had an account.

Anyway, there is a replacment for the Mage's guild. There is the Synod and the College of Whispers. The Synod horde magical items and use them to look politcally cool, and the College of Whispers poke Dadrea with sticks until they tell them things. The Synod just want stuff, they don't really care about "turf" and I think the Co/whipsers may actually be allied with the Co/Winterhold.

The Argonian assassin's you're thinking of are the Shadowscales. And as Veezara of the Dark brotherhood will tell you, they no longer exist.

As for the Fighter's guild, I suppose they could always turn to Skyrim and try to muscle in on the companion's contracts. Maybe they ran out of work elsewhere and are on the verge of disbanding or someting. But they can't really compete with freaking werewolves!