Economics: GO !
As with any new technology or method, the naysayers are at the ready to explain why the Cloud will never fly - especially pointing out the security risks.
I would like you to step back a little and ask yourself
* When was the last time you filled up your Diesel generator that provides "secure" electricity ?
* When did you hand a letter to your own mailboy to deliver a letter to your other office 700kms away ?
* When did you put your own fibers into the ground to have the assurance you have a "secure" telecoms network to that 700km-distance office ?
* When did you last time dig up a well to have "secure" water supplies ? Ya know, the commies at the water utility could Poison You Bodily Fluids !!!!!!
I could go on with police, firebrigade, schooling and many more.
Fact is, we rely on a large number of externally-provided services to function nearly perfectly and we are happy to entrust it our deepest secrets. The same Economics will make the Cloud a raging success. Why hire&manage sysadmins if you can just buy an Email, Groupware, ERP, File Storage SERVICE over the internet ??
We all know the current state of IT is messed up so much because sysadmins must be Jack Of All Trades in most shops. The quality of their service is consequentially shoddy and has an extremely bad price/performance ratio. The free enterprise system will drag all of us into a Cloudy Future, regardless of all the people who scream and kick.