I doubt SWTOR will EVER be Free to Play.
Subscription based is still a viable option. And subscriptions go up and down in between content patches. Please remember, we've barely hit the 3 month mark, and we're at 1.7 million subs.
Plus, we've had one content patch already, with another huge one coming in the next 2-3 weeks or so. Sub numbers will bounce up again after 1.2 drops. Its ALWAYS like that.