Turbine's Lord of the Rings Online has been fairly successful since its initial launch in April of last year, and the team is gearing up to release their first retail expansion, "The Mines of Moria". Along with the usual new quests, zones, weapons and raids, "Moria" will also bring two new classes to the game; the Rune-keeper and the Warden.
The Rune-keeper will be a high-level caster with both healing and damage dealing spells. The Warden is a brawler class whose combat will rely heavily on combos. Both classes will be available on day one when the expansion is released and both are said to be excellent soloing classes. Also, I hear they have a Cave Troll.