There are no closed source drivers in MeeGo, there are closed source drivers in device-specific builds of MeeGo which are added by the device vendor. There are four such binary blobs in the N900 image, only two of which are drivers (and both userspace.)

The problem with Silverlight is that you either get stuck with the closed Microsoft version or you are using the perpetually behind Moonlight. Ditto with Flash and Gnash. On top of that, you get to deal with Microsoft's saber rattling regarding software patents that are always vague.

Trusting Microsoft has been the downfall of many companies. It'll take a lot of effort on their behalf (that they have yet to show) before people, especially the open source community, will trust them.