> The hipster subculture is stereotypically composed of young adults who reside primarily in gentrified neighborhoods. It is broadly associated with indie and alternative music and genres such as chill-out, folk, modern rock, pop rock, and post-Britpop. Hipsters also frequently flaunt a varied non-mainstream fashion sensibility, vintage and thrift store-bought clothing, pacifist and green views, generally vegan, consume organic and artisanal foods, craft alcoholic beverages, and alternative lifestyles. The subculture typically consists of mostly white young adults living in urban areas. It has been described as a "mutating, trans-Atlantic melting pot of styles, tastes and behavior"
To me eyes there is definitely a large and distinct subculture with these characteristics.
To be a bit more judgemental, another good definition of hipster is "what happens when pastiche and irony exhaust themselves as aesthetics" (Rob Horning, also in that article.)