[wrs]

If GSM was not already broken, how do all of these products work?

http://www.google.com/search?q=gsm+passive+intercept

The point of the presentation is not that GSM has been broken; it's to make it so blatantly, obviously, publicly broken that the public (i.e., corporate IT departments) will have to pay attention.

[tptacek]

It seems likely that to the extent that things like the GSS-ProA suitcase interceptors crack A5/1, they do it with special-purpose hardware. A practical software attack is news.