A pragmatic perspective, imho; read the full post for more on privacy issues.
I think Google will only be successful with their program for schools and will have a moderate success only for small organizations.
Why? Businesses don't want to lose control oveir their information. Storing mails, documents, web pages on Google servers sounds tempting, but businesses want predictability and control. They'll also fear that Google's services aren't that reliable (Gmail has problems daily) and their image will suffer. "I couldn't answer you mail, dear client. Gmail was down for about an hour."