A feature for your thoughts. Notes in OS X Mountain Lion is designed for whatever’s on your mind. Think it up. Jot it down. Make it even more noteworthy with photos, images, and attachments. You can add, delete, and flip through your notes or do a quick search. Use the Share button to send your notes to friends or colleagues with Mail or Messages. Pin important notes to your desktop so they’re easy to get to. And take them with you everywhere. Notes works with iCloud, so when you create or edit a note on your Mac, it automatically updates on your iPhone, iPad, and iPod touch.
So glad to hear about this; I use Notes on my iPhone a lot, but I always didn't like it living in the Mail app.
But now it's going to be a stand-alone app, and easier to manage.