Modern Yarn (Exit 148) has Noro Kureyon Sock in stock in lots of colors – I hurried on over and got some! Here are colorways S40 and S149, plus some first impressions.
Kureyon Sock is single-ply, 70% wool, 30% nylon, 420 m (459 yd) and 100 g. It has a hard twist and a crunchy feel. The colorways look a lot like worsted weight Kureyon – Noro lovers will recognize them immediately. For example, here's Kureyon 149 and Kureyon Sock S149.
However, Kureyon Sock has a very different hand than Kureyon. It's somewhat like Silk Garden Light, somewhat like Donegal-style yarns – the closest thing I can think of is an old Rowan yarn, Kaffe Fassett Light Tweed 4-ply. I like a range of yarn textures, and I like this one (at least so far), but I imagine that knitters who prefer only very soft yarns, such as Malabrigo Lace (another single-ply yarn), will find Kureyon Sock harsh, even wiry.
There's a persistent rumor that Kureyon Sock is machine-washable, but the washing instructions on the ball band indicate that is definitely NOT the case. I'm guessing Kureyon Sock f-f-felts almost as readily as Kureyon.
Curiously, the projects that first jump to mind aren't socks. I'm thinking of Shetland lace and some colorwork (for which the nylon content is not needed). However that may be, I'm looking forward to knitting a bit and sharing the results – stay tuned.