Today, Microsoft availability of two Azure regions, in East Japan and West Japan, with geo-replication occurring between the two regions. These are now Generally Available (GA), so you can start using the data centers today. You'll see the two new DCs in both the portal and via API / PowerShell / CLI. For example, creating a Virtual Machine:

And here's output from the Azure PowerShell cmdlet Get-AzureLocation:

This brings the total number of data center regions to 10, with more coming (Microsoft previously announced upcoming regions in China, Brazil, and Australia