I do believe WoW will go free to play but not for a LONG time. I think when the subs drop to in the 20-500k mark blizzard will probably reduce/eliminate the monthly fee. I don't think they will close down the game completely given that the Diablo and Starcraft 1 servers are still up and running. Personally I do believe when WoW does go free to play no one will want to return/join because everyone who wanted to play has already jumped on the train. The newer generation will probably see WoW like we see older MMORPGs; amazing when they were released, but outdated compared to their standards.