The iPad Pro has a keyboard, and it can be purchased with it or later. I hear you saying that is nothing new; the iPad Air has its own keyboard too.
However, it is not as comfortable to use as the keyboard that belongs to the iPad Pro. I have both keyboards, and I can say that with the iPad 4, I preferred to use the virtual keyboard.
With the iPad Pro, I love using the keyboard that attaches easily to it. It feels like I am using my computer keyboard.
How do you attach it? Easy. The connection is on the side, and like a magnet, it aligns with the three points on the side of the iPad Pro.
Here is a picture from the side in my office with paper everywhere, but I am a writer.
Until the September 30th, be safe.