I applied a few weeks ago and received an accepted email yesterday. I created an account then i received another email within minutes containing the code.
They did state that only 2000 sites were going to be accepted. No one knows what their criteria is for choosing. A fellow publisher, who applied days before i did, still hasn't received any word. His site averages about 75,000 unique hits a day, yet no words. It's hard to tell what they are looking for.
It took me about a month to get a reply. My sites are pretty small, so I was actually surprised to even get in...maybe it has something to do with me spending a decent amount of money on ppc with them. My YPN account is tied to my Search Marketing account...which is cool because they offer money transfers for PPC...if only Google would get smart and add that. I'd spend alot more with them if they did.