It's been almost a year since Half-Giant races added and they have been very interesting and unique to roleplay as and roleplay with. With that, I would like to suggest Half-Ogre's to be added as a playable race for Surface and Underdark, there are Half-Ogre models exist within the game files or at least resembles such.
I for one not great at stats and possible bloodlines, I would leave that up to discussion.