I was delighted to run into John Hagel III as I hustled through the exhibit room at Structure during the final afternoon break. I’ve had the opportunity to meet John a couple of times over the years at tech conferences, and hear him speak on more than a few occasions. 
He is one of the most respected authors and speakers out there on technology and management issues, and always one of my favorites. John has a very impressive background (see above link) and is currently Director and Co-Chairman (with John Seely Brown) of Deloitte Consulting’s Center for the Edge.
John had been part of the opening panel on the first day: “Cloudonomics: The Value of the Cloud” (video here), which was fantastic. I actually tweeted that it made the whole trip worth it — which Om Malik immediately retweeted. Meaning I could’ve left then and been happy. But I of course stayed for the whole enchilada — and chatting with John was just one of the great side benefits of doing so.
One of the challenges of the cloud is security. Companies with highly sensitive data, or data that would be a likely target to hackers, will be hesitant to convert to using the cloud until they have higher confidence in data security.