A few retail MMOs have gone Free 2 play to a extent.
Removing the 10 day to 14 day free trials to use Endless Free Trial scheme. Limited to progression but unlimited play. I like the idea, more time to see if you can see yourself playing it long term playing for a sub.
Dungeons and Dragons: Unlimited (Now Optional VIP Subscription and Microtransactions)
Crimecraft (3 Models (Free, Basic, Premium) Each have their own advantages. With Free being strictly limited
Age of Conan (First Part of game free (20 Levels I think) - most recent one. Endless trial signups Only open for one month.
Warhammer Age of Reckoning (Endless Free Trial Model, First 10 levels and one area)