Grimm your part of the team has no problem, your art on renders i have seen for SA or KR looking great and also the stuff implemented in the 2d client.
The difference between 2d and 3d is not soo huge, a screen has only 2 dimesions. This so called 3d is a style of programming and art creating which should reduce work not create work. But also good painted comics are nice.
The problem i see is the engine used with the Enhanced Client, you are using sprite shaders in a 3d engine to render 2d animation sprites and this costs much performance, also simply drawing titles and textures without any bones cost much memory.
Then the problem with the server client communication, there is a simple answer why no other MMO like UO exist, the failure rate in communication is soo high, only one packet lost and no good exeception handler and the client crashes, and this for all items, houses, etc. But it is possible and Origin with Richard Garriott at this time created a legend, a dream, it is like Windows 95.
What i cant understand is the slowness of the event arcs or content creation, creating a monster with other stats and color is as simple as it seems two or three clicks, a spawner, a test, ready! Or changing elements like hitpoints, loot, skills, the enviroment or creating new champion spawns is easy. But instead of doing this things, the team creates new items, new enviroments, new monsters, why? I would like to see more revamp instead of 1 or 2 implementations a year!
The most important thing are not the model graphics, the effects are important they have to look cool individual, a splattering corpse, a cool lightning arrow cold shot or a nice fire nova shot, simple to create but a great game expierence.
But for all of this points, you need a solid fundament, the client! Excuse me but UO has no client with that potential, if you want to live the next 10 years, then it is 1 minute before the game is over to create one!