Binary package hint: ubiquity
A couple usability issues in Kubuntu Lucid installer:
1. The skip button which occasionally appears, shows up at the bottom, as a button with full window width, and it causes the window layout to change in a way that makes the slide show look jumpy. I think a better choice would be to put a standard-size button on the top (possibly on top of the progress bar to the right - on the same line as the changing description text). This would be more aesthetic with a normal-size button, would not change the layout/size of the window or its components, and will be more easily visible - near the progress bar and description text people look at, rather than at the far bottom beneath the slides, which is an area the user will certainly not be staring at.
2. The 'update installer' option (same for 'read release notes') is currently a web-style link at the bottom of the welcome page text. This is easy to miss, and also pretty much breaks the consistency, and the point, of using a wizard ('next-next-next' style). Instead, this should be streamlined into the wizard as the first step - for example, a checkbox on the welcome content page. If selected, pressing 'next' will do whatever updates it needs to do (if updates are available). If unselected (or installer is already up to date), pressing 'next' will continue to the next stage. The option can be unselected by default to preserve current behavior, but I think this is still better usability-wise, as expected by a wizard dialog, and harder for the user to miss.
Small addition: after running 'update installer', this option is removed from the welcome page (the link disappears). However, after pressing 'next' and then 'back' to return to the welcome page, the option is re-introduced. This too seems somewhat inconsistent.