I would like to see them expand PvP options to include the whole variety of gameplay.
- Dueling, where the most basic 1v1 feature ends with the other player being 'knocked out' and the find ending. We're not talking to the death, respawning at a wayshrine. We're talking fighting until one side ends the duel or is knocked out (lowered to 0 hitpoints, falls over like exhausted, duel ends, stands up and starts regenerating HP).
- Skirmishes, where smaller zones allowing fewer 'teams', preferrably two teams per alliance, fighting over cities and underground zones. This is more designed for capture the flag and objective based games (hold the territory, capture the flag, attrition, etc), and would be a much smaller, more manageable fight than Cyrodill would offer. This would also include PvE modes where one alliance is the only players (two groups of four working in coop), and the other two alliances have significant NPC presence on the map.
- Arenas. Spread throughout the provinces of Cyrodill would be fighting Arena's, with each Arena offering different venues, environments, and rules. Personalized to the zone, these could be two-versus-two, team-vs-team (4v4), team-vs-team-vs-team (4v4v4). It would allow fighting within your alliance (as it's not based on war, but competition). It would be structured around leaderboards and gambling. It would also include PvE modes to allow players to fight, not against simulated enemy teams, but against larger bosses and unique bad guys that would offer a significant challenge.
- House Wars would be where guilds were given the ability to declare war on another opposing guild, fighting wherever they found the opposition throughout Cyrodill. This might best be handled through NPC guild associations, like fighting between the Morag Tong and Dark Brotherhood. Or possibly through joining elite military arms of each Alliance, you set yourself as available for PvP even outside of Cyrodill. Must be rank 50+ and be in the veteran zones.
- Assassination contracts, where participating players (keywords, both players are voluntarily signing up to play as the assassin and the bounty, with both being rewarded for success) are allowed to hunt each other throughout Cyrodill. Not an outright PvP flag, but definitely could create interesting mechanics which could harken back to SWG and the Jedi vs. Bounty Hunters.