Total Biscuit has posted a video taking an in-depth look at the various races and character classes in BioWare's upcoming Star Wars MMO The Old Republic. He breaks down the classes and the race restrictions (for example, a Cyborg can only be a bounty hunter or a trooper).
The video also demonstrates customisation for both Republic to Sith characters, highlighting the cosmetic options that are unique to each side. For example: no tattoos available for Republic characters at all, so if you want ink, you're going to have to go Sith. In fact, it sounds as though the Sith generally have the more interesting customisation options.
There's a lot here, and eagle-eyed watchers will want to up the resolution to 720p to get all the info.