Read my edit, the bellow paragraph was out of ignorance, of the recent events.
I use systemd and I don't think this will affect eudev nor anything using dbus, anyway let's not turn this about it(systemd), I've been reading some about kdbus and from what I've read there will be a userspace daemon that will be a drop-in replacement for dbus but using kdbus in the background, anyway eudev pretty much is just getting udev outside of the systemd source code tree(search the git logs and see for yourself), for building it alone, and kdbus is an IPC system inside the kernel it isn't part of systemd, so you I think you are worrying about nothing in this particular case.
If you are not one of those people allergic to Lennart, here's a good video with *Technical* information about kdbus
 https://www.youtube.com/watch? v=NgR6d54blrU (join the space, the forum grabbed the video embedded with the complete URL)
Edit: I hadn't read your link, my bad, Well then there's things to worry about, for eudev, but I bet the the path will be to implement another kdbus userspace, but in my opinion while, this deafinitelly means a lot of work, it may not be a bad thing.