There was another similar thread to this, so pasting a edited version of my response to that here as well...
-Server-wide Arena: Great idea.
Instead of entirely removing the barriers and just making a common arena, why not keep the realm arenas and add a additional server-wide arena? Benefits of this would be incentive for the top of each realm to be going head to head, especially if the rewards were better. Also, it would allow active players that are "stuck" in their current realm arena slots because of large power gaps to bump up a few places and increase competition/movement/growth in each realm. Maybe there are only a certain amount of spots in the server-wide arena, and once you get bumped off you get sent back to your original realm until strong enough to try again or after a cooldown period, allowing people to decide which arena presents the best opportunity.
A single, server-wide arena would probably result in competition mostly at the top level. A server-wide arena combined with realm arenas would create competition everywhere. Greater rewards would be more incentive for people to strive for those slots, and the ensuing power vacuum left in the realm arenas would create opportunities for others. On the user-end this would bring a more dynamic environment. I believe it would be better for Tynon as well, as more growth opportunities in multiple venues would lead to more business. Also, you can never go wrong giving the top bread-winners more reasons to 1-up each other by pitting them constantly head to head. Perhaps it might also mitigate some of the server migration herd stampedes, as about 90% of the 'nerd rage quits' I've observed seem to be arena related frustration. Players will stay active on servers, even as part of guilds with hopeless odds of success in guild wars or sailing if they are still personally getting paid. Fact.
-Guild Wars
My current server has a server-wide guild war setup. It seems to promote a single, dominant guild while discouraging participation in 'lesser guilds.' I think the most benefit for everyone would be similar to the above arena concept. Let there be a choice of whether to march your guild onto a server-wide campaign or a realm campaign. This would create opportunities for lesser guilds to have a chance, thereby increasing activity and investment on a server. It would provide a buffer against the universally-hated uber guild. Entire guilds leave for other servers because the possibility of upward momentum stops (except for the players still raking in top arena rewards).
Think of it this way: it's human nature to want to be an apex predator, whether alone or in a group. The more opportunities you provide for that urge, the better off everyone is. It also dampens the herd migration, because I'm willing to bet that most server expansion is eaten by those 'heading west' for greater opportunities and freedom from their oppressors rather than new players. Unfortunately they leave carcasses behind, which simply take up space.


