If anything, what I'd like to see in games with face modelling functionality, that I haven't yet, is to allow the uploading of different head shots for ingame comparison while designing a character's face. Perhaps allowing you to silhouette a picture of yourself in the background, scale it to the model's head, and adjust your features accordingly. Doing this from multiple angles and shots should be a quick way to get a 1:1 representation of your face. Perhaps maybe even having a "real" mode ingame modeler, which allows the creation of a model's face with realistic proportions, and after you're done, the game engine "cartoonifies" or caricatures it to fit the game's artistic feel.?
Really looking forward to playing an FPS that for the first time ever (other games have only done this half heartedly), allows you to uniquely create your own model for online play!