So... I knew this day would come.
I've had OpenOffice for a while. I mainly use iWork for Office-type stuff, but there's some things where OO is better, in particular with formatting some Word documents. And OO is better at saving to Office formats too. In iWork I have to do "export" and need to maintain two copies of the same document if I don't want too much hassle.
Yet eventually OpenOffice on OS X became too annoying. My two most annoying favourite bugs were that when you start it, it says "Command timed out" and you need to click OK before you can move on. And secondly, it sometimes has trouble opening things from non-local volumes, such as SFTP-mounted volumes or WebDAV.
So I was looking for a way to throw it out. And the final push came when I could go to Carnegie Mellon computer store and pick up the student-discounted MS Office for Mac 2008 and install it. Bye bye OpenOffice for now.
I'll still keep using iWork over Office wherever I can. It is just so much nicer and less cluttered. And I think it's also faster. But sometimes you need to work with DOC-s with funny stuff in them, where iWork may not be able to fully make sense of it all, but you may need to do things like print them exactly with the formatting they were produced. So sometimes Office is a necessary evil.
And look how nicely the icons of Pages/Word, Numbers/Excel and Keynote/PowerPoint are together in my Dock without any fighting at all :) there seems to be some colorcoding going on here, I think Office started it a long time ago and looks like iWork followed suit, with "wordprocessing = blue", "spreadsheet = green" and "presentation = orange". (Well there's also other Office apps, but I don't really use them.)
UPDATE: another interesting thing that happened after installing Word is that Thunderbird sometimes displays a clown icon for Word documents. I have no idea why it does that, and doesn't seem to be happening elsewhere in OS X. Is it some political statement by Thunderbird people or what gives? :)