The Reader folks added support for including a feed in a folder when you subscribe (along with a number of bug fixes).
We also snuck in a small feature with this release: when you subscribe to a feed, you’ll get an “Add to a folder…” drop-down. This way, you can move that feed to a folder right there and then, without having to go to the settings screen.
As you can see, they placed the folder selection drop down in the subscribed status message. ...Which is much simpler (and better) than my go at it. Nice work.