You need to make it easier for your Evernote users to lobby app developers to get their apps working with Evernote.
Back in the day Evernote really had the app developer's mind share the way that DropBox has it today.
Your best users have dozens of apps they use that they would love to see working with Evernote!
My list:
Wunderlist: Ability to sync lists with a Wunderlist Notebook on Evernote would be powerful.
Tweetbot: Ability to archive my Tweets with Evernote for archiving
Suru: Beautiful visualizer for Tasks and sub tasks
TextTool2 - Full blown iOS