Far and few, you may want to keep an eye on this thread over at xda.developers
There are quite a few cases over in ebay. just search for SM-N915
I was able to lay my eyes on the Samsung OEM Note Edge case on Friday when I was in ordering my Edge. Very similar to their S5 case and it has a small pocket on the inside of the flap for a credit card or two.
Just as a follow up I bought the OEM Samsung Note Edge flip cover case when I picked up my Edge as they didn't have the Invisishield film in stock and wanted something to protect the screen in the interim. Bottom line I am not impressed with the flip cover case and will be removing it when I get a silicone back case and screen protector. Here's why...
1. The flip case plastic material has a much cheaper feel and appearance to the stock back cover (which you replace with the flip cover case).
2. The cover flap doesn't have any retention features on it (like a small magnet) which keeps it closed flush when not open. It is always opened a bit and not snapped shut like the cover for iPads and the like. There is a magnet in the cover to tell the phone when the cover is opened as there is a small sticker on the inside telling you not to put any credit cards in the flap for fears you will demagnetize the strip on the card.
3. The Note Edge thankfully works with my OEM Note 2 docking station which I use all the time at work and even with the cover installed it can still be docked but it just works better with a silicone back case and screen protector otherwise I have to hold the cover open to use the phone while on the dock.
One little tidbit of information is that when you register your phone with Samsung they send you a coupon for 50% off a single accessory from their store so you can always wait to receive that coupon and buy it direct from Samsung.
Bottom line the case isn't for me but it does the job while I research screen protectors and back cases.