It was in closed beta testing for a while, but was canned. Since then, A korean company bought it and is going to re release it to the U.S. Check it out, it's like Diablo 2(But free).
I may play Runescape more then any other MMO, But I have to say EVE Online is the best MMO I've played. SOOO much content, such a fun game (the economy is like the GE of runescape, but ON CRACK). plus finding and killing new comers is amazingly fun.
Other (Heroes of Newerth) If anyone has ever played Warcraft III: The Frozen Throne and played the game DotA, it's the exact same but with better heroes, graphics, game modes, etc.