Usually, I'm all for selling separate songs-- why should I pay for a whole album when I'm only going to listen to three or four songs? But when a request comes from the artist like this, it seems like a different ballgame. I'd like to buy Radiohead's album on iTunes, and if they want it complete, then that's the way I'd want to buy it. But because Apple has fought to keep songs separate, Radiohead isn't selling it with them at all. You might say that I wouldn't feel the same way about other artists, and you'd be right-- if Vanilla Ice required me to buy the entire To the Extreme just to listen to "Ice, Ice Baby," I'd decide it wasn't really worth it.
But my personal tastes aside, the whole thing actually reminds me of Ed Burns talking about watching Godfather on the iPod-- the iTMS has fundamentally changed the way we purchase and consume media. The concept of "album" is losing meaning. For most iTunes purchasers, I'd imagine that's not a bad thing. But artists like Thom Yorke and Radiohead clearly aren't ready to see the album experience disappear, and they're willing to keep their music off of iTunes to fight it.