What truly sets DDO appart in the MMO scene is its unparaleled variety of character builds, which is why this type of development should never stop, especially when there are is so much Core material that hasn't even made it to the game after all this time.
That being said, i am very happy to see that all the base classes from the PHB are finally in the game, there is even a splatbook class: the FvS!
As a side note, for those who don't know, the Expanded Psionics Handbook is officially declared by Wizards of the Coast to be a Core book.
This means that the Psion, Psychic Warrior, Soulknife and Wilder are core classes, included even in the Eberron Campaign Setting and are still missing from the game.
Dont forget Psionic Artificer!
Even worse is the absence of Setting Specific Races:
Kalashtar are not only setting specific in Eberron, essentialy unique in flavor but also are naturally Psionic.
Shifters are also setting specific, can be Dex or Str focused, make good Druids and are based on Werecreatures.
*Werecreatures have been missing from the game for far too long as well, considering the extensive role played by the church of the Silverflame in its inquisition against them. There is at least 1 Setting Specific Prestige Class that allows characters to become one.
Changelings are awesome for Charisma based classes, and its shapeshifting ability is mainly cosmetic, but could be a way to allow players to get racial benefits by emulating them.
Last but not least It behooves reminding that Psiforged Body is a Feat, so there is nothing stopping WF from developing Psionicism.