The easiest races they could likely add in are ones they already have in as NPC's. Two examples I have run across thus far are
. There may be others I have not run across yet, but if they already have the basic mesh modeling done, it's then a process of writing in the dialog, story-lines, and putting voice acting in for responses to those racial options. Which still would be quite a bit of work and cost on the Dev's side to implement.
As to classes, I personally would like to see all the psionic sub-classes added in as I feel they would fit the story-line well.
