This is a version of a powder that has been available in Australia for about a decade and was recently discontinued for the domestic market by ADI, the manufacturer. The decision by Hodgdon will see it back on the market in a slightly slower form. As mentioned by Ian, Hodgdon are marketing this with the Rem Ultra cartridges in mind.
I have been getting good accuracy and 90%+ loading density in my 308 Bear with the new powder. Cant wait until it is generally available. Should work well in my new Lapua 338 Imp too.