1) New player acquisition; all quests that are older than 36 months should be f2p, there isn't enough front loaded content to keep the causal player in long enough to convert into a premium. I am also assuming this old content isn't the bread and butter maker either (Account upgrades are the butter maker).
2) Entice casual players to spend a little bit of money each year; Go back to the seasonal adventure packs, 3 paid with a total value no larger than $10 each and a 4th that is f2p.
b) Upgrade the vip from Access Everything* to Access Everything! Favor rewards are a really nice touch and the f2p community loves it, but asking your VIP players to pay twice isn't. There are other account upgrades that the player loses access to if they downgrade from VIP, if they haven't unlocked it through favor when they downgrade it should be removed also.
c) Account upgrades, what's available to the f2p market is perfect, it's enough to get them through the game, but extras are a nice extension (so long as they aren't game breaking).
3) Keep an eye on the power gamers, see how they are spending their points, they go through them faster than anyone else, develop in that direction and give them options to enhance their end game (TRing has to be one of the most brilliant things in DDO). Just don't change the game as a whole to cater to this group (other wise the above two groups won't exist), give them more ways to demonstrate just how much better at DDO they are to everyone else (TR ladder).