This was a suggestion of the official AoC forums. Basically, build an arena so guildies can still pvp (it's not quite the same as dueling). Read here and please sign.

The Foundation takes its diplomacy very seriously. The Foundation wishes to stay Allied, Friendly, or Neutral with as many guilds as possible. Having enemies will only make things harder for our lower level members. Treating each guild we see with respect will allow The Foundation to remain considered...