Recently I got a Mac Book Air because my Mac Book was just way too big. I decided this time around I was going to try to not install MS Office on this laptop. The 80GB hard drive is already too small, and just didn't want to start mucking it up with bloated apps I didn't really need.
At work, I use Google Docs for about 95% of the usual document communication. For collaborative documents and spreadsheets, there really is no better tool IMO for a work environment. However there's that 5% of the time I just really need to use a client side presentation tool. The Presentations in Google Docs are again great for collaborative efforts, but sometimes you just need to use Powerpoint to drag and drop images, or deal with standard PPT templates or whatever.
I tried, I really tried to use Open Office. I installed it on my Mac, with no MS Office, and I tried to use it exclusively to create my presentations for the last month. But it didn't work out. With all the latest versions and patches, it just couldn't render the standard template we use correctly, and our standard template is really, really, simple.
So here I am installing Office 2008. Sigh. Maybe next laptop.