MMORPGs are pretty cookie cutter when it comes to player character options.
When I see the announcement for Bless mentioning the Naga, my first thought is "I want to play one of THOSE!" That goes back to Naga in Warcraft, 2 not "World of". But even in games like WoW there are a lot of enemies I'd love to see playable. The hyena-like Knolls and Dryads from the Elven areas are great examples from WoW. I'm sure if Murlocks were an option people would jump all over that as well. What we get are reskins of the same old thing though.
And that's only race options. There are a variety of Roles players don't get the chance to fill. The Operator in a modern or futuristic setting is something I'd like to try. Have some drones providing different views of the mission area to alert players of imminent danger or opportunities. In a few games you can run your own shop or tavern, but the choices are limited. What about Fixers?
What options would you like to see in your favourite MMORPG?