It's a good idea, and I've been thinking of it as well. With VPC, you will need to manage a handful of VPC-specific networking constructs, such as internet gateways and routing tables. These are interdependent with other services such as NAT or a VPN server, which are deployed as EC2 instances. Deploying all of these services at the CPI layer while retaining the benefits of BOSH is an interesting challenge.