I love the "cards", or at least, the step in that direction.
Just like Apple Numbers, it seems to point to a future paradigm of software development IDE experiences. Something a lot more freeform, flowy, than a traditional file/tabs UI. Some files are 2k lines long, some are 10 lines long; some are text, some are data; it's time we stop cramming everything into the same square file editing box. I think there is room for a lot of innovation here in the UX of developer tools.
Was very excited to see that.
We wanted to show people what we were working on, warts and all. We are super aware of what you're bringing up. The "cards" especially are not the metaphor we intend to use, just a shortcut to get this in front of people. I hope you'll bear with us :)