I would imagine Chrome OS would be at least comparable in user experience to Android.

Microsoft's pockets may be deeper, but if the open source developers of the world like what Google is up to, Google could potentially have way more resources available for its efforts than Microsoft does.

My understanding is that the plane is fly-by-wire, thus would the pilots still have to exert the same physical force they would need to exert if the plane's controls were mechanically connected to the flight control surfaces?

Perhaps Google is simply waiting for the right, most profitable moment to break everyone's trust...

Protecting the envelope sender protects from bounces being sent to a spoofed sender, though there are other ways to do this on the sender's end.

Potentially SPF, Sender ID and DomainKeys could be used in concert since there are no conflicts between them with the exception of Sender ID's re-use of SPF v1 records that may not have been written with Sender ID's PRA in mind.