uhh....
do you really want users to have the ability to install any software on their local machines without your knowledge. i dont know, in my opinion, this could lead to alot of problems in the future for you because who knows what they will install if they have administrative priveleges.
as much of a pain in the butt that it probably is, having to install the software for users, i would say that giving users the ability to install any software that they choose could result in alot of security and performance problems on your network.