The more things change...
...the more Microsoft seems Hell-bent on continuing to play the same-old dirty-pool... while pretending (poorly) to be an "innovator", and Saint.
The simple fact is that "Silverlight" IS MS-proprietary, intentionally-limited, and specifically designed to lock people into Microsoft-controlled products. It does not, and (if Microsoft has anything to say about it) will not, exist on anything other than Microsoft approved (obviously, non-competing) platforms. And, it doesnt actually provide anything that isnt, basically, already available.
Currently, we have "Flash" running on several different versions of Windows, AND Linux, AND within many different browsers, without any problems (and, "Flash" obviously exists throughout the "Mac" ecosystem). This is because, even though "Flash" is also "proprietary", Adobe isnt tied to PUSHING any specific platform upon consumers (unlike, Microsoft)... nor does any company have as much documented-history (as Microsoft does), of doing exactly this.
Frankly, "Silverlight" IS directly-tied to Microsoft-specific technologies and methodologies (as it was designed to be). In fact, this reminds me of when Microsoft attempted to get motherboard BIOS companies to fundamentally alter basic BIOS-operation, itself, to directly reflect MS-Windows-specific APIs, or, when Microsoft began proposing new "internet protocols" that were, also, actually tied directly to Microsofts APIs.
And, I think all of this is, clearly, part of Microsofts latest push for their, so-called, "Cloud Computing"... which will basically eliminate the Windows-OS in favor of a (strictly Microsoft-controlled), perpetual-payment, "thin-client", "computing-environment"... which will actually turn computers into nothing more than Microsoft-services delivery-devices (Microsofts perennial dream).
So... this is just the same-old... business as usual, for Microsoft.