I got excited when they first started talking about this feature. But it turns out that it doesn't do what I hoped.
Me and my partner live at the same address. Both have individual iTunes accounts, different debit cards.
She buys some music, I buy some music. I want us to both be able to share the music. Why would we buy the same album from iTunes twice?
Yeah the only way to do this is to either share an iTunes apple ID or set up both or your purchases to use the same credit/debit cards.