A new study says nearly two-thirds of respondents indicated they didn't pay anything for the download.
The problem with any statistics about the Radiohead experiment are that a lot of people are going to go try it out even if they don't know Radiohead as a band. The upside for Radiohead is huge - lots of people get exposed to the band that might not otherwise have listened.
I haven't tried it out - I don't really care about Radiohead. But if I did, I would probably give them a couple of bucks. 1) Hey, it's more than they ever would have gotten from me in this life; and 2) if I like it a lot I can buy it again; and 3) I might not like the music at all, so a couple of bucks is a small risk to take on the music.
(I've been downloading lots of Amazon Unbox to my TiVo for $0.99 - in fact, two weeks ago I downloaded four movies and I've only had time to watch two. For $0.99 I'll try lots of movies I would never otherwise touch.)