Steve Ballmer is convinced that Google Apps is nothing to worry about -- according to Steve(24 minutes in), "you can't even put a footnote in a document". Perhaps what happened directly after he said that is precisely why Microsoft should be worried.
About 2 days after Steve downplayed any kind of competition that may be coming from Docs, Google added footnote support. The agility, and horsepower that Google has behind it is something that companies -- even Microsoft -- should be wary of, and definitely shouldn't take lightly.
It's true that Google Docs hasn't yet challenged Microsoft as much as I'm sure they would like, but don't count Google out just yet. This is how I see it playing out over the next few years:
1) Google perfects their entire Google Apps suite (which includes Google Docs, Gmail, Google Calendar, etc.) by getting it to a point where it could theoretically compete with Microsoft 2) They make everything available "offline" 3) The Enterprise Search Appliance will be no longer just for search -- it's will be an enterprise class server that you can deploy internally to host Google Apps
Once Google reaches step 3, there nothing stopping them. Companies will have the power of Google Apps which is by then able to compete with Microsoft products, and deployable within their company infrastructure. Users won't have to worry about downtime (unless it's actually their own problem), and all that data is completely out of Google's hands and available without an internet connection.
Perhaps this is why all Google's stuff is still in beta? Do you think Microsoft has anything to worry about with Google Apps?