Probably the most practical idea Firefox has had to maintain and possibly build up its market share in a long time.

Well, you read one of their goals and visions here. That part is ok.

The question is: how is that goal turning out once it meets reality?

Tons of great ideas failed for various reasons. Alan Kay keeps on pointing out how sad he is that Xerox PARC failed in many ways. Reality is a strong selector - and the evil Google empire will make competition really, really hard here.