Control Windows Azure Load Balancing and Request Routing.

The Windows Azure Traffic Manager CTP is a new feature that allows you to load balance traffic to multiple hosted services. You can choose from three load balancing methods: Performance, Failover, or Round Robin.

Traffic Manager will monitor your hosted service on any http or https port you choose. If it detects your service is offline it will send traffic to the next best available service. This feature will allow Windows Azure customers to more easily balance application performance across multiple geographies. Using policy management you will be able to route some traffic to a hosted service in one region, and route another portion of your application traffic to another region. 

Read more about it here. And register for a webcast that covers it here.