A few weeks ago I noticed changes in browser's behaviors… 

1) My IE  7.0.6000  no longer prompts for Click To Activate  :)

2) My firefox 2.0.0.13   no longer required a reboot after installing Silverlight …  If you had not noticed, using silverlight.js on IE allowed you to instantiate silverlight plugin right after installing , but on other browsers it required a re-start… 

I pinged Piotr, our deployment PM, asking if he was seeing the same and he upped it sharing that he had a way to instantiate silverlight on ANY PLATFORM and ANY browser WITH OUT requiring A RE-START…  [call me a geek, but I was happy]..   Today, he posted the blog with the magic call: navigator.plugins.refresh () …   Check it out yourself…  

I hear the  next version of Silverlight.js (when we next release an SDK) will include these changes; in the mean time you can take his advise and use navigator.plugins.refresh () to get around the re-boot issue and instantiate SL right after installing…  

[caveat: this does not work if silverlight is being updated, and the plugin was loaded, but that scenario is not common since silverlight auto-updates itself] …

Thanks Piotr, and welcome to blogging..