I imagine that many Evernote users put information into Evernote that is far more personal and sensitive than they would ever put on Facebook, for example.
This should be the litmus test of the level of security that should be implemented in Evernote. Forget all the fancy features that may be exploited by 1% of users, focus on the 100% of users - security of sensitive information. Get that right first, then enhance the product.
Evernote should be more secure than social media applications, at the very least, and should be as secure as banking applications, in my opinion.