I would argue that non-Linux enthusiasts won't find anything special about the N900 versus the latest crop of Android computers. Non-Linux IT practitioners would be better off with a UMPC Windows computer. Advanced business users would be poorly served by the current business functionality of the N900, especially in the PDA area.

This could change over time, starting with the rumored feature upgrade to the OS (rumored because I haven't seen an official announcement as to when it will be released or what ti will include). It could also change as the development community releases more apps to the platform. I would still recommend that your additional users take a wait and see attitude.