I have said it before, there is no piece of development in this game that should be prioritized over the inclusion of gnomes. They are a basic component of D&D and ought to have been in place long before now.
Remember when the game launched and there were no dragons and the running joke what "Dungeons & No Dragons:Stormreach" ? In my opinion the fact that 8 years in we don't have a core race is that level of wrong.
Are there other races that would be fun? Sure! A number of them. But gnomes should be in place.