Amazon just announced an extension of their VPC (Virtual Private Cloud) service to include virtual networking and Internet access capabilities. So what, you might ask? One of the criticisms previously of cloud computing for some companies was the inability to segregate your servers, data and applications from all of the other shared services on the cloud providers infrastructure.
This new capability from Amazon now allows this segregation. Set up a whole private network on the Amazon Cloud with public facing and private servers, powerful network configuration around IP address ranges and subnets and routing, and even protected access to data on Amazon S3.
It begs the question: "Why would you NOT consider moving services into the Cloud?"
See Amazon announcement.