Cyrodiil is fun, but only when the battle field is level. People lose moral when one faction guests into a campaign, then destroys everything without being much of a challenge. Also, when one faction owns all of the scrolls and majority of the keeps, it really buffs them up to be more powerful than anyone.
Here's a list of ideas on how to make PvP more balanced, which would be more fun:
1. Buff factions who own less than (x) of their home keeps. Something like an Unyielding Spirit would allow factions to have a fighting chance against a faction who owns most of their keeps. It doesn't have to be PvP specific, but maybe something like (x)% more damage to guards and walls/towers in their home keeps. This would make it so that players could attempt to retake their keeps faster and easier.
2. Add a debuff to the Emperor when there is less than (x) allied players near him. An Emperor should not be able to fight and kill 20 players by him or herself. The Emperor can't be an emperor without his subjects.
3. Add a limit to the number of "guests" in a campaign at one time. Some campaigns are being destroyed by guilds of factions that jump into guest, or friend campaigns, just to harass the opposing faction. I don't have a problem with it, as long as it's not an overwhelming number of guests slaughtering everyone.
4. Being able to "blood teleport" to a nearby keep should be removed once Forward Camps return. The ability to die to guards to teleport to a distant, disconnected keep is abusive. If your current keep is cut off, then a Forward Camp should be used if you want to stay there and fight (or you can, you know, not die).
With the updates to Cyrodiil coming in the next patch, I hope siege weapons are buffed to the point that a trebuchet can 1-shot a (low level) player if they don't dodge the shot.
If I see any other ideas in this thread, I will add them to this list!
Off-topic side-note: Trebuchet is marked for incorrect spelling... Spellcheck fail!
Thieves guild coming soon?! All in!