Maybe I don't understand how the service works.  But the way I understand it is, I type in the name of someone I wish to make a deposit to (i.e., 0x), then it gives me a bitcoin address to send the BTC to.  I send the BTC, and away I go.

But what would stop me from registering as 0x, and potentially mooching off of people wishing to send BTC to you?  Or Ox, to grab typos?