Purchasing and Currencies
11.17 Apps may facilitate transmission of approved virtual currencies provided that they do so in compliance with all state and federal laws for the territories in which the app functions. [Emphasis added]
The reality is that Apple's Guidelines change isn't likely to result in Coinbase, Blockchain.info, or any other service bringing a wallet to the App Store any time soon. It's anyone's guess when that bolded clause above can be satisfied, but at least Apple has spelled out a position grounded in reason and logic.