Darn,
I can't imagine a company going to the trouble to R&D something and then not producing it.
It currently was listed as IN STOCK at their site, but when I went to order it it said not currently available.
There are a couple other US sensors available for the Arduino stuff, and for those of us who would like to drive a post in the ground and do some real winter measures, I don't think that would be a choice for me right now.