Star Wars: The Old Republic's 1.6.2 patch notes are now live on the game's website. Along with a laundry list of tweaks and bug fixes, there are a couple of blurbs that might interest free-to-play players concerned about character slots.
First of all, slot restrictions are now being enforced, so free players should see a maximum of two per server. Preferred status players get six slots per shard, while subscribers get 12. If you must know, the global active character limit is 350! The Cartel Market is selling additional slots at a cost of 600 Cartel Coins.