Another small idea we realized for openSUSE 11.1 is a link in the first-login greeter to a "Introduction to KDE4" page.
Originally written for the greeter (hence the current layout and shortness) the text ended in the wiki because we were past openSUSE translation freeze. The wiki solution also allows extension anytime (feedback and translations welcome). Its purpose is to give new KDE users and KDE3 switchers some (openSUSE-specific) explanations and hints for a good KDE4 start.
For further generic introductions and tutorials we happily refer to the nicely growing KDE UserBase. 
Syndicate Blogs
great idea
this is one of those things that keeps getting punted by the plasma team as we continually end up with "more important" things to work on, but having an introduction available to the user right on the default desktop is such a good idea. kudos to providing this for your users.