It is a lighweight VM and uses the same technology as Firecracker
> Can I run a GUI inside of it?
It is planned but not yet implemented. But it is absolutely possible.
> Do you think of this as a new Vagrant?
I would consider Docker for VMs instead. In a similar way, it focuses on dev ops type use case like deplying apps, etc.
> How do I get data in/out?
There is an SDK and server that help does that and file streaming is planned. But right now, you can execute commands in the VM and get the result back via the server
