It is always such a mystery which writers have an enduring reputation, and which do not. Novels (and novelists) at least tend to stick around, in some library at any rate, but poets drop out of circulation very quickly once their books are pulped. Playwrights are in a different spot where you might well be able to find their plays in a library, but then they are never produced. For younger, contemporary playwrights, these days (as tough as they seem) probably have more outlets (due to more small, upstart theatre companies outside of the big cities) than before.
That said, it is awfully rare that I actually get to see any particular play I am interested in. I have found myself traveling quite a bit to catch Tom Stoppard plays. I made a trip last year to see a revival of Arcadia, and I am just back from a fantastic production of The Coast of Utopia. This was a marathon event, running from noon to just shy of 11 pm. I will definitely be blogging about this later, but I should mention that they extended the run by a couple of weeks, and added one more marathon day on May 3, for anyone else crazy enough to make that trip.
However, many writers do drop out of sight or are never really part of the canon to begin with. And so much of this is context-specific. Some authors are never really known outside of their country (particularly if not translated or translated well into English), or outside of one part of a country. I've encountered a few B.C. writers and poets whom I would probably never have heard of in Toronto. I've only recently learned about Michel Tremblay and Robert LePage -- and only managed to see one play by each of them. Their reputation (particularly in the U.S.) is quite limited by their being from Quebec and, naturally, writing in French.
What inspired this post is the (near) utter disappearance of the French playwright
Caryl Churchill will probably still be read, at least in university classes. I'm far less certain of Eric Overmyer. I think his most enduring play, On the Verge, really does have to be seen rather than read. And being seen on stage is still such a rarity, even if there are more opportunities than there used to be. It's such a shame that copyrights and performance issues prevent more plays from being videotaped, so that interested parties could stream them. If only there were more of a market for that. Well, something to consider in another life when I start up my own theatre company...