[sorkvir]

There's actually 3 reasons:

first, the sphere's are meant to intermingal (sp?). What you will see will be more adventuring area's that require a high lvl diplomat (Nesibue Necropolis and the levers is an example of one already in the game).

Masks. I believe that masks are around the corner (seriously). Pretty much these are customizable jewelry that you can wear and swap pieces out.

Prestige faction: This is like a bank account. The plan is to use your prestige faction to buy items. As for what, I'm not sure.

There's actually a few more but those are the 3 that stick out in my mind right now.