Samsung had an unexpected hit on its hands with the Edge display on the GS6 Edge and Edge+, but that was all because of how it looked; there was hardly any additional functionality tied to the curved screen. With the Android 6.0 update (and upcoming Galaxy S7 Edge, I'm sure), Samsung is adding some new features that make the Edge display more worthwhile.
The current edge panel is 260 pixels wide, which is barely enough for a contact image or app icon. The new edge panel is 550 pixels wide. That's enough to display news headlines, stocks, sports scores, and more. You will be able to get 10 apps in the new edge shortcut list, and even include entire folders. There's also a new "tasks" edge panel with various tools like a compass, flashlight, and a ruler (which I think is kind of hilarious). The little tab that triggers edge mode is also more customizable with adjustable size and transparency.
You'll have to wait on the Marshmallow update on your device to get any of this, but the good news is that Samsung is starting the Marshmallow rollout today, February 15th. The bad news is that it will vary by region and carrier approval. Maybe you'll be able to buy the GS7 Edge before Android 6.0 hits the GS6.