1. Creating tasks in notes editor by simply clicking the checkbox icon in the editor controls adds checkbox at insertion point. Tasks may be checked to show done/todo state in edit mode.
2. In view mode, the checkboxes appear, but may not be checked.
3. Tasks may be filtered in the notes browser. Interestingly, Evernote even found checkboxes in the PDF of Luke Wroblewski's Forms ebook as well, and though they were to do items.