As part of GSoC 2013, I'll be writing the Portfolio Plugin for Evernote. This would help users to export the Forum posts to their Evernote accounts. You can find the specifications here.
The link to the tracker issue is CONTRIB-4338.
Currently, there is a Moodle Repository for Evernote. The link to the repository is here. This repository was developed by Frédéric Massart. This helps in downloading a file from Evernote. But, as such, there is no plugin available for exporting the Moodle content to Evernote. This project would try to develop the Portfolio plugin which helps users to upload the Moodle content to their Evernote accounts.
It would be great if you can give in some of your views or additional features that you think might be useful for this plugin.