One of the stranger things in the world is which authors endure through the centuries and which ones don't. I spent the hour drive home from the airport yesterday contemplating who from 1950-2004 will be considered part of the "literary" canon in 2300. Its a tough question.
Shakespeare was primarily an entertainer. The economic model dictated that his works needed to appeal across society. There's little evidence that he intended to write great literature (his poetry may be an exception). He wrote to build and keep a paying audience.
Poetry is dead. Plays are dead as literature. As presented, they form a unique form of entertainment and message. But reading a play will be seen as a quaint 20th century oddity. The novel is on life support in terms of sales numbers and social penetration. The Nanny Diaries and the Da Vinci Code are fun, but are unlikely to be in high school English classes. Shakespeare only published a libretto since he had no alternatives (otherwise he would have been quite pleased with his DVD box set).
What is left is the movie (the short story) and the TV show (the somewhat lower quality -- for now -- long form). Will students complain of having two hours of 20th century TV shows for homework every day this week? Will students learn to construct visual stories as the successor to the written stories of middle school?
When will technology slow down such that visual stories can be seen as modern for a century rather than 10 years? 1970s TV shows look awful today. As do most movies. Will the 2002 remaking of Star Wars (redoing the special effects) be the last, or only a gapfiller until the 2035 remake? Or will television be regarded as an archaic art form after replacement with a 3D alternative, just as the radio serial is today?
My view: I think hiphop will be the surviving poetry of the early 21st century (and Eminem may well be poet laureate). It will seem as dated and stilted as iambic pentameter does today, but the kids will like looking up the dirty songs after class. And some TV show which we do not expect will be a foundation of the canon (I can't believe we have to watch two seasons by next Friday!).