Writing a full review based on a day's worth of listening seems foolish, so let's keep this rather concise: Based on first impressions, this new Radiohead album is very good—surprisingly good, even, considering the uneven, overstuffed Hail to the Thief. But quality is not the biggest surprise the band's seventh album has going for it.
For me, the most shocking thing about In Rainbows is its relatively conventional sound. Maybe some of that has to do with the fact that Radiohead's style has been aped so much in the past decade that music like this was bound to sound standard. But more likely, it's because this music is practically Bendsian. Yeah, most of the songs are infused with "electronica" and the band's other latter-day calling cards; they represent an evolution more than a devolution. And yeah, the album's impending release has been just as hyped as the band's previous records. Yet In Rainbows sounds much less like an event than Kid A or even Hail to the Thief. It just sounds like a really good album.
In fact, it sounds like the album many fans were hoping for back when Kid A dropped. Thom Yorke's apocalyptic paranoia is still a factor, but he's channeled it into music much warmer and more welcoming than the often grotesque, impenetrable sounds post-millenial Radiohead had been known for. In Rainbows offers less horrific images and sounds for the band's less adventurous listeners to wade through. Perhaps Yorke siphoned off some of that darkness by making The Eraser, but even that record was less twisted than expected. More likely, he's been moving in a new direction.
You could look at this music as confirmation that Kid A and what followed were as much about subverting people's expectations as creating beautiful music. (Kid A, and to a lesser extent Amnesiac and Hail to the Thief, did both.) Perhaps now, as we saw earlier this year with Wilco, subverting expectations means returning from the experimental edge to a comfortable, populist sound. Or maybe, as both bands would probably tell you, these are just cases of bands following their muse back toward pop, no ulterior motives attached.
(OK, so that wasn't exactly brief, but this is Radiohead—what do you expect?)