Allow install SL without admin rights
Chrome can install without admin rights, and even has support for pdf and flash. All without any admin rights.
Allowing install SL without admin rights will allow Silverlight to beat Adobe quickly, as one of the major reason business (medium and large ones) hesitate to use it is because not everyone has it installed. One of the reasons Google Chrome becomes so popular is it doesn't require admin rights to install.
herzmeister der welten commented
i think at least _some_ updates could theoretically be done without admin rights. if the core engine stays the same and only some controls are improved, it should be possible to update without admin rights. to achieve that, the plugin dll would have to be split into modules.
admin rights are removed to stop dangerous code being executed on the machine, technically Silverlight could be dangerous. The ideal situation would be that Silverlight would not require a plugin, like HTML5... but then you loose the flexibility of the .NET platform.
Many users can't get Admin rights due to many reasons.
Why disqualify these users.