The new Apple Nots app is interesting, but I am very confused as to why Apple did not include any import or export function? I am running DP 4 of Mountain Lion and I can't import any of my txt notes into Apple Notes.
After upgrading my mac to 10.8, I look back people who are using the long-loved Thunderbird. This might help to export notes.
1. In the Mountain Lion's Note.app, drag and drop all iCloud notes into your Google account.
2. In Thunderbird, install an extension called "ImportExportTools"
3. Select your notes and right click them (once) to export all.