Then there's Microsoft
Then there's Microsoft who does it both ways. They've got Office Web apps that work through the browser with collaboration support and file format support that works much better than Google Apps. The've also got the online file storage and syncing with Live Mesh (who's beta version actually had a web-based desktop interface.) Then there's the full Office Suite for people who want both online SharePoint/SkyDrive/Cloud connectivity/collaboration as well as offline access and powerful processing tools not available in any web app. It seems like Microsoft has all bases covered, huh?