According to StephenReid on the SWTOR forums, SWTOR will have same gender romances added to the game post-launch. They made concessions about what to include pre-launch and what to postpone until after the game is released. He goes on to add that several other features and other content will be added later such as additional companion characters etc.

While this isn’t a must-have for any game, it’s nice to see that they don’t exclude anyone from enjoying the game the way they wish to play it.

Official statement follows:

Due to the design constraints of a fully voiced MMO of this scale and size, many choices had to be made as to the launch and post-launch feature set. Same gender romances with companion characters in Star Wars: The Old Republic will be a post-launch feature. Because The Old Republic is an MMO, the game will live on through content expansions which allow us to include content and features that could not be included at launch, including the addition of more companion characters who will have additional romance options.