Indeed, will be nice when something blocking in one window doesn't lock up the whole emacs process.

YES! E.g. try running emacs on $host and run bbdb; go to some other machine and ssh ~/.bbdb $host:~/.bbdb; then ssh $host emacsclient. Now it's unresponsive until you walk over on your feet to $host and answer the revert-or-not question :(

Yes, ohhh, yes, I want that!