Dead? Not yet. Dying? Absolutely.
I left the game last year (after 2-3 years of playing), when the Galactic Command System was introduced, like many others.
I just returned to check things. Everyone is saying that a lots of players is returning for the double xp, CXP bug and such, and the servers have "population spikes". I don't know, on every planet I see less players when I left the game, so if this is a spike, i don't want to imagine a normal state.
I don't think SWTOR is a bad game, in fact, it's a good game, that's why it's still alive. However, i don't know what happened to Bioware, but the current game/marketing policies are ridiculous and killing the game. Short-term opportunism (douple XP, free month) will not work on long term and cannot save the game. Revamping the whole free to play system and solving the dead servers problem might.