According to Ohlen, BioWare put a premium on bringing several core components of KOTOR into SWTOR. He mentions epic narratives set in the Old Republic era, cinematic storytelling, being a Jedi, owning a starship, traveling to different worlds, an internal conflict between good and evil, and hanging out with companion characters that actually matter.
Here's a clip from the post:
All of these were key elements that we knew we wanted included from the very start of development. The good news is that all of these elements are featured prominently in SWTOR. These features also make SWTOR unique amongst MMORPGs, and helped forge what has become one of the strongest game communities in the history of online RPGs.Players of SWTOR can join in the celebration of KOTOR's birthday by purchasing the Revan's Heir title from the Cartel Market for 10 Cartel Coins. The title will be available only until 3 a.m. EDT, July 16th. So, tonight. Additionally, you can read through some of the memories offered by people who worked on KOTOR and score yourself a handful of wallpapers on this official BioWare post.