I know this may be a sore point in regards to how the last project ended, but the concept is solid in my opinion. World of Warcraft is a perfect illustration to how people get drawn into these virtual worlds. The idea is to create an MMO with a crypto based currency to use in it that people can actually use. It really blurs the line between the virtual world and reality, but online gaming is a booming industry. Think about it the "mining" you do in WOW could be actually use your cpu to mine coins for use in the game and real world.

Not really any original ideas, but I think a project like that would be huge.