That's just another thing we can't get an answer on - they say they've "known from Day One" who it would be, provided "it makes sense" which may mean some Classes get new ones as the SGR option.
However, "we want to do it right"... plowing through to 50, then meeting some brand-new sidekick and racing through their story arc on just one planet (assuming it's in the Makeb patch)... I don't know, that doesn't seem like it'll be up to par with the existing standard.
"Everything's still on track, this year" - in the absence of any follow-up info, that's feeling more and more like "What we told you was true.. from a certain point of view." will be the gist of a Yellow post come February.
Hence my earlier comment that I personally think that by this point in time they've been postponed indefinitely. I do believe what the dev said last year that they had written lots of content, that might even have included SGRs, but I'm not sure that we're ever going to see it, certainly not in the way it was written (now that F2P has come along, and the move from class story to the nice and vague avenger story) and also not without a riot from our part.