Just a quick update, order notes have been added to 1.1 of Printable Invoices.
Next update will include selectable options to control what store details appear in order invoices, as described in this Idea. As a side note, Product Importer Standard has been updated to 1.2 with support for Plugin update notifications.
Update: Migrating Add to Wishlist to a WordPress Plugin this long weekend, stay tuned.
