I find it suprising that so far no one has really addressed the question. I work in local government as a sysadmin supporting about 40 different departments. In the last couple of years I am seeing a trememdous move to asp.Net/SQL web applications that appear to be much better than what they replaced...mostly  Tomcat/Apache or IIS setups. Also seeing some of our major vendors, Motorola (they do a lot of 911, Law Enforcement stuff) and New World Systems are basing their apps on .Net.  If you go to Microsoft Business and dig around you will find many more.

Recently our Court system moved from a DOS based system to an asp.Net application that integrates with Documentum imaging, the migration was extremely smooth. Only problem now is our Chief Justice has decided everyone has to go to a application being developed in the AdvantagePlex environment to stay synched with  the original AS400 app that the state used, and it is already obsolete before even being implemented. They are at least putting a asp.Net front end on it that may well replace the 300MB client in the long run.