The little I've heard of Radiohead I'd say no. As I laid out in another thread, for me and I think generally accepted too, there are certain conventions prog rock is expected to satisfy (not enumerating them all again; anyone who knows prog understands what I mean) and I don't see RH fulfilling those. I would never have thought of them as a prog band personally, but I don't know enough of their music to make that determination. In the end though, does it matter? If you like them, cool. If you hate them, cool. Me, I'm off back to my home planet, where they need me.