Comment 41 for bug 366398

I can confirm comment#35
It's exactly the same on Gentoo running 4.2.0.

This makes most applications completely useless when they're run using 'kdesu'.

Opening file dialogs just shows:
"Could not start process Cannot talk to klauncher: The name org.kde.klauncher was not provided by any .service files."

Trying to send a mail via KMail shows:
Sending failed:
Unable to create SMTP job.
The message will stay in the 'outbox' folder until you either fix the problem (e.g. a broken address) or remove the message from the 'outbox' folder.
The following transport was used:
 <email address hidden>

D-Bus has autolaunch support, the running D-Bus session is even started with the '--autostart' argument.