EDITED: I've Been Using Guild Incorrectly. Guild is now "Buisness" in most instances. While I still want to create Guilds, Buisnesses are now in this thread.
Anyway, I had the idea of the player being able to create a guild. Now, this would be done from the "Capital" city (like how the Imperial City was in Oblivion), and would follow a pre-designed template, which follows:
>Guild/Buisness Name: XXXXXXXXXXXXXXXXXXXXXXX
>Guild/Buisness Focus: Examples
-Fighting
-Alchemist
-Magic
-Real Estate (I don't know)
-Brothel (Once again, for teh lulz)
>Base Property:
*List of owned properties*
>Finish (Pay X gold)
After completing this process, you would be given a guild charter, in which you would be able to sign members into your guild. However, the stronger your guild/buisness, the more your competition will clash with you, some diplomatically, others violently (I.E, rival Fighting buisness will attack violently, Real Estate buisness will try to negotiate with you). From your base, you could make an Insignia, and forge this Insignia onto weapons. Just like upgrading things like in Bowerstone Castle (Forgive me if the name is wrong) in Oblivion, you would be able to buy upgrades for your guild hall, for a hefty sum of gold, of course. There would also be properties better suited for being a headquarters, such as Castles, and you would be able to keep a base in multiple locations the more powerful you grew.
So... what do you think?