beat isnt a style
social commentary wasnt started by the beats, and i dont honestly feel that social commentary as a goal is something that defined the beats. i feel that what defined the beats was something broader that may have included social commentary, which is the attempt to arrive at the essence of thought and behavior thru unconventional prose or poetry. kerouac even went so far as straight transcription of taped conversations.
reality bites certainly has beat-type subjects as did salinger. the american young-persons angst thing can definitely be traced back to the beats. hippies, slackers, whatever...but these subjects arent necessarily intentional throwbacks (speaking of the reality bites generation) to the beat generation as much as they are a stage in the progression of what started back in the late 50s.
to define a beat subject, i would seek to understand the subjects of kerouac's books, which, as the touchstone for the whole movement, introduced many of the characters of that time in that sort of light. a beat subject, to me, is a person who feels disillusioned with society, who feels like they are an outcast, who sees or attempts to see the more fundamental motivations of the people around him, including those from who he/she feels separated from, and who attempts to live their life based on the artistic expression of these beliefs. meaning, the subject does not necessarily need to be an 'artist' per se...the definition of art here is meant to include the intentional, thoughtful, coordinated and goal-oriented expression of anything, including a way of life.
as a rule, i try to stay away from defining anything, certainly anything current, as "beat." one of the big things about that generation is that they were trying to set out specifically new ideas. in order to see the influence of this generation on current works of art, i would tend to advise that you define this influence in an allusional manner. current art isnt so much molded on exactly what the beats may have done, but there are certainly quotational tools that are used by today's writers or filmmakers in order to tip their hats to that very influential movement.
all artwork borrows from past artwork. dont get too hung up on labels. but again, beat is not a style. beat was more a way of approaching and dealing with the structures of literature and art that were in place back then.