Is there any way to get samba4 installed without uninstalling kubuntu-desktop? I'd like to play with openchange to get mapi working in KDE, but sudo apt-get install samba4-common gives me:
The following packages will be REMOVED:
kubuntu-desktop samba-common smbclient
The following NEW packages will be installed:
samba4-common

Though I've read that 'kubuntu-desktop' doesn't necessarily remove KDE? Is this true?

I'm on a semi-fresh install of kubunutu jaunty.

Yes it is true. 'kubuntu-desktop' is what Debian and it's derivitives call a 'metapackage'. That bascally means that it provides no files or software itself, but depends on a group of packages, forcing them to be installed when you decide to install it. It is perfectly safe to remove them, though you may have apt/aptitude/etc. trying to uninstall them automatically as they're marked 'auto-installed' and will be considered orphaned once the package that depended on them is removed.

You can usually fix this in synaptic (don't know if adept has something similar) by going to to the "status->installed(auto-removable)" section, selecting everything (make sure there's nothing there BEFORE you install samba4, if there is make note of it or remove it then) and under the "Package" menu (I think, maybe the one to the right of it) and unchecking "auto-installed" or something similar.