It shows everything from the dialogue system and its consequences to working in groups. Land vehicles are present too in this 11 minute long walkthrough.
The diary was released for E3 this week. It follows a Sith 'sorcerer' who's looking for a long lost Czerka research facility. It's a great glimpse at the MMO and what BioWare has been up to all this time. Check out the dev diary below and the 'Eternity Vault' trailer.