I've thought for a while about your post, and although I agree that the "public's interest has moved on" somewhat, I don't think that the situation is a hopeless as you've painted it here.
What I have to offer as a counterargument is myself and the thousands of people who do subscribe to the magazines. I love much of the short fiction that some of the folks who've posted here say have caused the death of short fiction. I love twisty, complicated stories filled with clever characterizations and nuanced effect. I think stories with cool ideas that leave me thinking for the rest of day (or week or month for that matter) are worth reading. I love perfectly matched language to story. And, when I find stories I like, I want to keep them on my shelf, because phosphors are temporary (look at what happened to the SCIFICTION archive, for crying out loud).
I love the feel of the latest issue of Realms of Fantasy in my hands, just as much as I like that I can tuck an Analog inside a notebook to read in class. Getting the latest issue of Talebones in the mail, or ripping open the plastic to get to the next Weird Tales is a positive joy in my life.
Also, I don't think Kelly Link, Connie Willis, James Patrick Kelly, Paul Melko, Howard Waldrop, Neil Gaiman, Jay Lake, Carrie Vaughn, David Levine, Paul Marusek, Ted Chiang, Mike Resnick, and about a hundred or so other contemporary masters of the short story should drop what they're doing and move to other art forms, like writing for video games, movies, television or books (which are an entirely different form of story telling).
The short story is too cool to write off that way.
So, as a reader who loves those magazines in their print form, and as a writer who is honored sometimes to appear in them, I think they are worth helping. I don't think that "no one is reading short fiction" anymore is accurate, but I do think that we have to work hard to find the ones who might be interested, and, as always, to appeal to the up and coming readers who may be reading Harry Potter now but will want to read other cool stuff later.
If the print magazines go under, and all short fiction moves onto the web, it will be a sad day. I don't think it has to happen, though, and if a little active effort on my part may prevent it, I will do it.