I still think moving fields closer, creating more interesting terrain to fight in, and removing barriers to player fights such as heavy flak, will keep players more interested. The arena should foster player interaction, period. The fields are so far apart now, it takes a good 20 min to find a good fight. There are few neat terrain features to draw players together to fight. The flak often drives players away from areas where they would otherwise find people to fight. All of this degrades gameplay because it discourages player vs. player interaction.
It makes the arena boring.
If I want to fly around enjoying the view, not seeing other players for 20 min at a time, and having AI push me away from places where I might encounter other players, I'll fire up second life. I play AH to have player vs. player encounters, and anything that discourages that will keep me out of the game. It's been a problem for a couple of years (IMHO) and it's even more obvious now that the arena is split into the three war periods. There is no reason why 32 people in a mid-war arena shouldn't be fun, but when I logged in, it was a 20 minute flight to another empty field over flat featureless terrain, only to be beaten back by heavy flak as I approached the other field before I ever saw an enemy aircraft. Oh joy.
What happened to the good old days when you could take off, set auto-climb at 5 deg nose high, and arrive at 10k over the enemy field and find 10 willing opponents battling in a deep canyon, on the side of a mountain, or in a volcano? That was awesome. Never find that nowadays, since a 5 deg climb will get you to the enemy field at 20k+ assuming the flak doesn't shoot you down en-route, over nearly featureless terrain.
Bring back the 4-cornered symmetrical WB 1.11 arena... That was fun. I never wandered around the arena looking for a fight back then, and I never worried about some AI shooting me down during a dogfight. It was me and my friends vs. the other player and his friends, in an interesting terrain environment. That rocked. Why don't we still have an arena for players who just want to play at air combat?