Today I Am Reading a Book. My first thought was: Nooooooo! There is no way I'm going to stop reading when I get old. (I can just imagine people saying: You're young. Just wait until you do get old. Then you'll see how boring books are!) Or maybe it's just temperament and book preferences. If you only read books when those books are by Big Names, I can see how reading could become a chore.
However, it's interesting how the author of that post comments on her own blog about "a myspace culture which concocts the self out of consumables" as a justification for reading Big Names. Is she trying to say that reading commercial or genre fiction a bad thing? Or is it more like Ray Bradbury's message in Fahrenheit 451?
I read the linked post and disagree (also could do without the F words and name dropping, although those are just pet peeves of mine). I am not old, although I am quite a bit older than you - and I read just as much as I did when I was younger. So does my sister. My grandmother was an avid reader almost until her death (at 89), as was my aunt (who died at 67). My 73 year old uncle is always reading books. I think my tastes have changed somewhat over the years, and in some ways there are more demands on my time so it can be a challenge to find the space to immerse myself in a book, but I still love a good read!
Fear not and fret not. Reading into old age is as common as not doing it.
I'm still a voracious reader (I'm reading "The Blue Sword" right now actually, since I always give someone's favorite book a spin - unless it's something silly like "Ulysses"), and will continue to be. Children cut deeply into your reading time, but they are the stuff of life, so that's ok. The beauty of the reading habit is it fits all the gaps you find in your life. It's always there when you have a moment. No booting. No waiting past the legal warnings. Etc.
As for the woman who posted, I think the issues lies in WHAT she read, not that she reads. Save for Greene, Flaubert and Mann, most of what she read appeals to the young and those who haven't seen the wheels of the world turn yet. Once you get some age on ya, Nietzsche, Marx, and anyone associated with post-modern philosophy expose themselves as the whip-heads they are. Their prose and ideas are sexy until you realize not one of them dealt with the world as it actually exists.
Also, as you age, you have seen some story cycles done to death, and you typically favor the first one you encountered. It's the same mechanism as hearing a song. If you hear the cover version before you hear the original, you are likely to always prefer the cover as it was your first experience. Original stuff just gets harder to find.
Therefore, authors with legs, like Vonnegut and J. Irving, and whomever you admire, are that much more valuable because they are almost always complete originals.
I'd wager you will be an avid reader until the last book false from your elderly grasp.