Re: Transactions will be by far the more important application in the long run
I'm having a hard time coming up with any case where not knowing the party you're contracting with would be a good idea. If you don't know who the other party is, then the contract is unenforceable. There's no way to force someone that you don't know and can't find to honor a contract.
The only use case where this seems even remotely useful is in a criminal enterprise, where you're already at substantial risk of the other party reneging on the deal.