Apple has also gone in this direction for some of their Mac apps. The latest iMovie, for example, is "always saving", and doesn't prompt the user at all when the application is closed. At first, I found this a little disturbing, as I'm conditioned to either save then close, or close then be prompted to save.

The only reason a developer might not want to use this kind of behaviour is if they are not confident that the number of undo steps they can save will be sufficient to cover one scenario many users are used to: they save the document, then make a lot of very messy and difficult-to-undo changes, to the point where they just want to start over, so they just close without saving and revert to their last-saved version. Even if the system is storing a lot of undo steps, it may not be able to bring you back to the point you want because you haven't saved manually to establish a version of the document that you're definitely somewhat happy with.

Perhaps instead of either "the user is in charge of saving" or "the system keeps track and the user can't manually save at all", a solution would be "the system keeps track and the user can also save to indicate ideal rollback points for the document", something like OS rollbacks.

In Europe?

In theory, yes, but if the extensible functions are written using natural language commands like the examples of "map these" and "twitter this" then there should be a near-negligible learning curve.