Fluther is a bit hard to say but its unique and sufficiently catchy. I would stick with it.
To expand you should try attacking some focused niche areas.. Make it highly useful to a small group of people first.
Good work
If you allow anonymous posting (and manage to control spam at the same time), you could have a winner. People hate to register to do a simple thing like asking or answering a question.
The UI is nice and easy to use. Great job there.
The designer cult has trained people to think small fonts look more professional or classy or something. Big fonts are jaunty and friendly. It suits this interface perfectly.
Otherwise jsjenkins is spot on. Niches can be a valuable place to gain traction.