This is an interesting vision. Not concrete in a lot of ways, but you a lot of the core ideas seem at least somewhat plausible: http://marshallbrain.com/manna1.htm
The first story seems more plausible than the second, but I hope the future looks more like the second.
I agree with you, but I won't share your optimism until I start seeing way more ideas for what this future would look like that are way less hand-wavy than what I've seen so far. Vonnegut's "Player Piano" feels a lot more familiar than Star Trek's no-scarcity-or-need-to-work-but-everything-is-amazing.