Probably the major featured change is the option of teleporting back to the entrance of an instance.
Starting in Game update 1.4, when you leave the Flashpoint by any means, you will be offered a teleport back to your adventuring location IF you have killed at least one boss in that Flashpoint (or in some cases, hit a significant checkpoint).
This will be presented in a menu – players can choose instead to jump to the entry of the Flashpoint (in case you want to just jump to the Fleet to repair, for example).
There will also be a two hour delay to binding items in which they can be exchanged. Hence, the problem of an accidental roll is now over.
A new cosmetic change in the new update will allow you to set mood for your character. Typing /alarmed or /cheery will set your character’s facial expression permanently.
There are also other changes in the update. You can read them in detail on SWOTR’s blog.