SQL Azure Merge Replication

and if the Sql Azure Data Sync Service doesnt meet your needs, you can always write your own...

see: Walkthrough of Windows Azure Sync Service Sample

SQL Azure Database does not provide replication currently.

http://msdn.microsoft.com/en-us/library/windowsazure/ff394115.aspx

However, there is the SQL Azure Data Sync service (currently in preview).