I always thought LED keyboards were stupid because they are useless, but if they could map to hotkeys in video players and such, that could be very useful, assuming you can turn off the LEDs.
His idea for centralized application configs and keybindings isn't bad if we could standardize using something like TOML . The Options Framework for Wordpress plugins is an example of this kind of thing, and it does help. It won't be possible to get all the semantics agreed upon, of course, but maybe 80% is enough.
Resurrecting WinFS isn't so important, and I feel like there'd be no way to get everyone to agree on a single database unless every app were developed by one team. I actually prefer heterogeneity in the software ecosystem, to promote competition. We mainly need proper journalling filesystems with all the modern features. I liked the vision of Lennart Poettering in his blog post about stateless systems.
The structured command line linked to a unified message bus, allowing for simple task automation sounds really neat, but has a similar problem as WinFS. But I don't object to either, if you can pull it off.
Having a homogenous base system with generic apps that all work in this way, with custom apps built by other teams is probably the compromise solution and the way things have trended anyways. As long as the base system doesn't force the semantics on the developers, it is fine.