I am kind of partial to Johnny Cash covering, well, almost anything, but especially "In My Life". I think when he realized that he was close to the end, he really saw those recording sessions as opportunities to reflect on his life, and took full advantage of them. The Mercy Seat's great, Hurt's good, though I have heard it too many times.
I just think the fact that his recording set-up was so simple, just pick up a guitar and go, along with the fact that he was known for covering other writer's songs, gave him an opportunity to get so many great moments on tape that most artists could not pull off, because recording for them requires so much advance time to write and hone material, and get big arrangements right.
I don't think Neil Young's really "near the end", but I hope that he will take a similar approach in his twilight years, just throwing on tape everything that comes to mind, and then culling out the best stuff for release.