Since this looked very interesting and there's no demo (or naughty version) I searched for an alternative.
There's a free program which works in a similar way:
Rapid Evolution by Mixshare
It's java based, so not the fastest program around but I just pointed at my current techno mixing folder and set it off on a batch analysis. It took about 1/2 hour.
Then I saved the ID tags back to the .mp3s and fired up Traktor Pro.
In TPro you can add the "key" id tag to the default list, so then you can order your tracks in key.
Another thing that is really useful is this
harmonic mixing chart.
Using that in conjunction with the Key tag in TPro makes it very easy to keep mixes sounding great on the fly.
I guess this is the sort of thing that you get an "ear" for anyway, but with a big folder of tunes, it makes it really easy to select the next track and keep things harmonically lurvely.
Even with minimal techno this works pretty well - i'm going to download some house next and try it on that, I suspect results will be more impressive...