We are excited to announce support for Elastic Network Interfaces in Amazon VPC. Elastic Network Interfaces are virtual network interfaces that can be attached to EC2 instances in your VPC. You can use Elastic Network Interfaces to run dual-homed network appliances in your VPC or create a back-end management network for your public facing instances. You can also move an Elastic Network Interface from one instance to another and network traffic to that interface will be directed to the new instance.
Please visit the EC2 User Guide for more information on using Elastic Network Interfaces in Amazon VPC.