If you need some detailed examples of how all of this will work, look no further than the latest Ask Cryptic for Star Trek Online. In this edition of the venerable community-driven question and answer bonanza, the focus is firmly upon visual and statistic customization choices. Yep, that's right, not only will we be allowed to make a character with ridges and point ears -- we'll also be able to make them psychic or resistant to poisons as well.
Want to make an android? Go for it, the creation process very much allows you to achieve it through visual, technical and story avenues. About the only limitation will be our imaginations and the classic Trek adherence to bipedal abundance.