About the cable on my old HD201 -- it still works, but the insulation has turned brittle and is coming off everywhere, so yeah, it's disintegrating. There's also a problem with the cable at the stress relief on the jack, which causes the sound to cut off sometimes (but rarely).
But then again, my HD201 ended up in this condition after more than 2 years of (ab)use as my primary headphones. I thought about having it recabled, but I also ended up giving it to my cousin.