Bioware said they're contemplating bringing it back since it was so popular and people have been asking for it. How they bring it back though remains to be seen. Don't expect it to be free unfortunately. Unless they bring it back instead of Double XP weekends.
I would sub for it, I'm enjoying plaing the republic side especially for the new story content but the slow grind sucks. The XP bonus I assume would allow people just to do the story missions and not have to do too many side quests
I have 2 lvl 50 imperials from when the game launched, I am kind of at the point where I'm thinking I should just get the expansions and level them instead