It's the very same wool used to construct the Jan Sweater:
Apparently, it's spun from the fleece of the Exmoor Blueface (whatever that is), which lives on the moors of North Devon. It's "a lustrous yarn with a soft handle, great stretch and excellent stitch definition". It's processed by one of the few worsted fibre processing and spinning plants still operation in the UK in conjunction with Susan Crawford, the genius behind the Stitch in Time series.
Talk about your awesome cross-promotion.
I haven't yet begun to knit with it, so I can only tell you how yummy it feels from on the skein. But you should know that I imported the very same wool used in the beautiful styled Jan Sweater shot, above, for about 30% less the cost of the wool I purchased in a local yarn store in TO ($45.00 vs. $65.00). I also got a discount for having pre-ordered A Stitch in Time, Volume 2, as yet to be published.
Money well spent, I say.
Update: I was mistaken (which is to say I must have misread) about the Jan pattern and its appearance within the second volume of A Stitch in Time. Apparently, it will be included. So feel free to wait for the book to come out. Or just go for it and pre-order now!