The irony of TESO is that their game already has the answer to it's PvE problem. It's essentially Cryodill. If they had based TESO PvE on using the same philosophies that can be found in Cryodill, it would have been a pretty awesome MMO. Since levels are agnostic in Cryodill, progression and content would be essentially gated by gear and skill progression/acquisition. This increases player freedom. Factions wouldn't be separated, thus opening up other lands to explore at any time and expanding the immediate size of the world. Overlay that change with a three faction system, and it had the potential to provide a Velious-like experience. Finally, Cyrodill lacks phasing removing yet another gating barrier. This is oversimplifying what would need to be done to make it work, but I think this is also why there are a lot of people that enjoy Cyrodill in the first place. It feels more like a MMO.