A couple of days ago, I came across a blog post and a message board thread that had similar topics - Is today's science fiction more or less relevant than the so-called science fiction classics?
In both cases, the answer was that Science Fiction that's coming out today is better than older works that have come out. In the case of the blog entry (which I'm having trouble finding at the moment), it was that older science fiction is no longer relevant, poorly written and not worth reading at all. The message board thread was essentially that films nowadays are far better than older films. I tend to disagree with both arguments, as I feel that older works have just as much, if not more, to offer to fans.
When it comes to literature, SciFi has a decently long and very rich history. Exploring all aspects of it, in my opinion, and disregarding certain aspects of it is a foolish thing to do.
I don't disagree that older Science Fiction can become very dated. As science progresses, the genre has become far more sophisticated, and very detailed as to the science involved, while spreading out to encompass much more than just physical sciences - social, psychological, etc are all featured. On this level,the arguement is far stronger.
Yet there are aspects of science fiction that cannot be ignored. I for one cannot fathom calling myself a fan had I not read the works of Asimov, Herbert, Heinlein, Wells and numerous others. These authors, while having their flaws, provide elemental aspects of the genre. Wells provided the entire foundation for alien invasions, Asimov provided his Three Laws and Herbert introduced some of the best world building and political tangles that has helped legitimize the genre. Without these building blocks, the modern science fiction genre would not exist as it does today. There's good books and short stories out there today, but they owe a lot to these older works.
The films is a slightly different argument, one that predicates more on the visual appeal of Science Fiction films - there can be no doubt that with the introduction of CGI and computers to the film industry have revolutionized how films look, and elements are far more realistic. However, I once again disagree that the films nowadays are generally better. They look better, but when one looks at the major blockbusters that are out nowadays, I can see that the story is often sacrificed and watered down. I would honestly doubt that there has been a film that is as good as classics such as Forbidden Planet or 2001: A Space Odyssey, although there are certainly several that have come out recently that might rival them at some point - The Fountain, maybe, perhaps Children of Men or something along those lines.
I don't think that modern sophistication and writing, while typically more relevant to today's society, is necessarily better just because of that. There are certainly good works being created, but it is important to remember the past of the genre.
EDIT: Io9 found the link and wrote up their own article on it: http://io9.com/5040839/is-sf-too-obsessed-with-its-history