The problem with google style cloud computing is the lack of privacy.
A solution would involve the separation of the data hosting and ap hosting.
The ap would be downloaded onto the personal computer, and the data would be accessed using a private key that only the user has. The ap manipulates the data, and is uploaded and encryped so that the data center can't access the data either.
The problem is that google style content based ads won't be possible, and gmail style indexing won't be available either.