If you've got the time, IGN has a four-part video series showcasing The Old Republic, in the developer walkthrough shown at GamesCom. The video shows three classes and their attributes, multiplayer dialogue, the "flash point" story mechanism and much more.
Twenty minutes is a long time to take a look at a single game. But being that The Old Republic is an MMO, and considering the unbelievable amount of time players will be spending with it, this is just the bat of an eyelash.
A larger size of this is available at IGN, where the videos will play in sequence automatically.