I use Kubuntu 9.10. Whenever updates are available, I have to always click the button at the bottom of the list to select all available updates.
Would it be better to select them by default? I think this might be easier for novice users, or those newer to Linux (like myself).
Power-users who know a bit more about specific packages can then choose what to deselect, thus putting more complex decision-making in the hands of those who hopefully know better.
This isn't a PackageKit thing, it's a kpackagekit front-end thing. You need to open a bug on KDE's bugtracker, using the component kpackagekit.