Any standard that requires D-bus is a failed standard.
No, it's actually great idea to use D-bus, because it's not available in BSD. It's Linux community that's driving FLOSS and there's no contribution coming from BSD tiny word. Just ask KDE, Gnome or X developers about this or check which bug reports are meaningful. For example: PC-BSD has debugging disabled while even Ubuntu has this turned on (which makes Ubuntu vs BSD benchmarks quite unfair).
We can use dbus today. If kernel bus implementation is successful it shouldn't be any problem with a port to it when the dbus inteface is done.
The only good thing about dbus is the precedent in introducing other generic client ipc (other than pipes and sockets). Maybe now plumber will get ported and we can finally have small and sane programs again.