Many people write on non-existent stuff, usually called "fiction" - not sure what it's doing in the Philosophy section...
Generally I side with Habermas on this one: Modernity has not yet spent its potential.
I would recommend his book on the topics, of course, as the best we have!
http://plato.stanford.edu/entries/habermas/
You can see Chomsky's objections to their "obfuscations", too, I suppose...
http://www.cscs.umich.edu/~crshalizi/chomsky-on-postmodernism.html
http://cognet.mit.edu/library/books/chomsky/chomsky/5/8.html
[Oh, I learnt a lot in this guy's seminar:
http://www.mzos.hr/svibor/6/01/013/proj_e.htm]
All else is a lot of... bullocks...
Btw, have a look at this, also:
http://plato.stanford.edu/entries/postmodernism/
The name escapes me now, but I think the guy who invented the term was a Dutch journalist, if memory serves. He later abandoned it, together with many others, realizing that a new epoch does not start with sticking a "post-" prefix to a current one...
And I don't buy the bull about the prevailing tertiary industries somehow almost automatically meaning a new epoch, together with some changes to the ownership structures of society, in terms of "many little owners mean a radical difference" somehow, when in fact the very notion of ownership isn't even being challenged at an elementary level...
Then, there's the people who feel that it starts the minute you extract yourself from your surroundings, by, say, shoving a headphone set onto your head and listen to your MP3s or whatever...
It's all very unambitious and just not at all serious, even though Habermas gives them the time of day and entertains them handsomely...
You know, when you come to a Human Rights conference and a "post-modernist critic of it all" starts and finishes his lecture by impersonating an aeroplane or just sits there and refuses to say anything... Oh, well...
This is as far as I would go wasting my time on the subject, really...