Considering that Scoville unit is defined as number of units of water Jim Scoville has to drink in order to disipate the heat and I doubt he can drink 2 million units of water over any sane period of time.

The definition I'm reading is the amount by which it must be diluted in order for testers to be able to taste it.

I'm guessing the million-Scoville march people have managed to extract pure capsaicin and put it into some hair-raising product. Supposedly pure capsaicin (N-Vanillyl-8-methyl-6-(E)-noneamide) ranks 16,000,000 on the Scoville scale.

[link|http://easyweb.easynet.co.uk/~gcaselton/chile/scoville.html|This page] has a possible explanation for how the millions of scovilles were arrived at. (Most of the way down the page, followed by a big red block that says only an idiot or a chemist would do it. :=)