What are the main tenets and/or beliefs of the 'Emergent' Church?

'Emergent' is a word I see gets thrown around a lot. Is there any definition to what is and what isn't emergent? - Is it a catch-all for certain points of view? - Are there people out there that actively identify themselves as 'Emergent'? - What are, or what is considered to be the main tenets and/or beliefs of the Emergent Church?