Split the OS into different services. The file system, the run-time (EXE) management system, the UI manager, the coordinator, etc. For one, you could mix and match and pick the best part for your needs. That's a more webby and cloudish view of things, I would note.

I do agree our file-systems need to be more RDBMS-like. I'd like to see "Dynamic Relational" experimented with more. You don't necessarily need to pre-wire columns: add them as you need, unless not permitted for a given table.