To my knowledge there are not any MMO's which allow you to alter your clothing/ armor appearances in game to suit your vanity.
I think Second Life allows you to do such things. Well this obviously comes down to $$. Atari doesn't make a dime off all the community content. One could argue that the strong community improves sales of the game and it's expansions. I'd agree. But still Atari must believe it's leaving lots of dollars on the table when it see just how many small "mini MMO mods" there are. Some of them are truly excellent.
If there were ever a mmorpg that I might play it would be one of the NWN franchise. However I don't know much about 4th Edition but from what little I've read about it, I wasn't overly impressed.
The PvE elements need to be excellent. I assume they would start with the Sword Coast. Neverwinter, Waterdeep and Baldur's Gate with surrounding areas would be a nice start. Expanding that out through to the Dragon Coast in a future expansion. Undermountain, Underdark (at least one Drow city for appropriate characters to start), The Abyss and Nine Hells should be accessible areas to high and epic level characters (hmm devil PCs might be an interesting idea). The FR setting makes it near impossible to run out of content to quickly deliver.