To me the $64 question is how many people would feel comfortable with any of the new calendar services if they knew:
1. For regulatory reasons, service providers aren't throwing away any data collected by their Web sites. (Pat Helland, now of Amazon.com, said this in a keynote yesterday at the Software Archictecture Summit.)
2. The U.S. government and other governments increasingly subpoena all sorts of information from service providers. Heck, sometimes they don't even need a traditional subpoena.
"But I was just trying to synchronize my calendars because the software wasn't doing it for me...and calendar sync service X was free..."
But as they say, sometimes, when you're up to your neck in alligators, it's hard to remember you were originally trying to drain the swamp.