Licensing For SQL Cluster

Hi,

I would like to setup a SQL server failover Cluster as described as URL below.

http://msdn.microsoft.com/en-us/library/hh231721.aspx

Understand that there will be 2 servers and shared storage are required.My question is do I need to 2 SQL Server license with CALs or just 1 SQL server license and CALs is enough for my condition? Because I heard that if the SQL is setting up as  failover cluster for any kind of SQL Server database work,there's no need to license the redundant hardware,So would like to confirm for it.

Thank you and looking forward for reply. ^^