Much is being made of Google's tieup with Sun which, as I understand it, will improve penetration of OpenOffice. Now, I'm no techie, but I have used OpenOffice, and there's no way it's going to be a serious challenge to Office in the near-term. Despite the hype about Office portability, OpenOffice fails to open highly formatted content appropriately, and lacks many of the features that Office has.
I understand a lot of people are anti-Microsoft (I use a Mac at work because my advisor is one of them!) But the reality is Microsoft makes a good product, and has the scale to automatically give it an edge on competitors. Yes, Google has those same attributes too, plus the "cool" buzz, but it's going to take a lot more to unseat Microsoft.