Adobe AIR has been installed on over 200 million computers in just 16 months
I've missed the Flash Camp Keynote in San Francisco where Adobe CTO Kevin Lynch mentioned that AIR reached over 200 million installs.
The Adobe AIR Team blog wrote that the Acrobat.com application provided with Adobe Reader continues to be one of the most popular applications.
Unfortunately in Italy AIR applications are not so populare and well accepted by enterprise companies (this is the market I work for) and I guees we'll have to wait more time in order to see the same penetration you're reporting in US.