The one thing I find missing in evaluating whether to move from MS Outlook to apps provided by Google as a complete SaaS model is integration. The Calendar doesn't talk to email very well; adding contacts is clunky, etc. Perhaps the entire model is just not as clean as Outlook. But after watching the demo of Salesforce.com working with Google, I may be more convinced that a switch is coming. Of course, I'm looking at the demo for when maps will pop into the dashboard that you can create showing sales progress, etc. Ok, the demo didn't give maps any attention but someone else has. There have been mashups around for a few years but the recent announcement between the two companies have indicated that the integration is already there. SaaS in a Web 2.0 world is nothing new but the latest solution from Salesforce.com/Google is making an even more convincing argument for shelving client side apps.