I don't think a lot of the people posting on these forums understand what a real "profit margin" is. EA is all about one thing, profit, and as long as this game keeps a steady subscription base this game will be profitable. I imagine most mmo players out there perceive a successful subscription ratio to be around 8 million and up, mainly because you've been playing WoW too long, but all Bioware needs to do is keep a bare minimum subscription rate that nets profit and EA will keep forking out more cash for further updates & expansions. It's a figures game, the forum opinions really don't matter to EA, they just want the profits and they'll get it because the Star Wars brand is one of the top entertainment brands in the world.
So I don't see this game going free to play, because EA would never support a free to play mmo that cost as much as this game did to create. As far as the 10 years mark, too early to say. You can venture a lot of hypothetical opinions on what the future holds for ToR, but the only thing that is certain is EA and their lust for a profitable game, if the game stays profitable the game will continue.