I have been a Linux user for past 10 years, and would never boot a Windows machine except I work on one ever day for my company.
The missing component for a complete conversion on my work desktop computer for work is a scriptable publishing program.
I use Quark now, with Xdata import plug-in.
Scribus is probably workable if I was proficient in Python.
Next years project.
uggg Python is nasty ugly stuff ;) Jython is even worse. We are cutting over from Weblogic to Websphere and I am almost daily pained by how cryptic the admin interface is made by its reliance on jython..
InDesign on OS X. Sweeeet. You can use AppleScript and JavaScript, both quite easy to learn. If you have a generated XML source it can automatically build pages based on it.