I'm of two minds as to the closing of the Oscar Wilde Bookstore.
On one hand, I have fond memories of the bookstore from my coming out. In 1983, I started graduate school out of state and was just coming out. To explore this strange new world, one weekend I took the Suburban Transit bus from Princeton to New York and the subway down to Greenwich Village. While chain bookstores in malls already had small LGBT sections, those sections were dominated by Gordon Merrick and remaindered relationship guides; they certainly provided nothing like the wealth of information available in a gay bookstore. Also, the cashier's reassuring smile is burned into my memory to this day.
On the other hand, it is no longer 1983, and we have progressed such that LGBT literature is widely available both in general-interest bookstores and online. While some people complain that we are "a movement, not a market," as though those two things were mutually exclusive, I believe that such progress shows how far mainstream society has come in taking our concerns seriously. Institutions often outlive their own usefulness or even render themselves obsolete; there is no reason why bookstores should be an exception.