Well, the Eberron campaign guide is here. Well, it’s mostly here. Currently, you can pick up a PDF version of the guide, which is called Wayfinder's Guide to Eberron, on the DM’s Guild by clicking the link. The current cost is $19.99, and having had a quick look at it, I have to say that thus far, there is quite a bit to enjoy.
What I’ve read so far is well-written and engaging, and there appears to be quite a lot that I will want to use. It also makes me want to run a setting in Eberron, which is saying quite a lot since I am mainly a homebrewer.
However, there’s a bit to unpack when it comes to exactly what this book is and why there is not currently a hardback release, as one might initially expect from a D&D release from Wizards of the Coast.