I've been crowing about this all over the Internet.
My friend Tom Block was the origin of the idea, but I think I was the first on the Internet to make the argument that The Wire was incorporating many overt direct references to The Wild Bunch, especially in Season 2.
I awoke this morning to David Simon confirming this on NPR.
Here's the earliest mention of the two that I can find on the Internet. That's me in the comments. My friends and I had been kicking the point around for a few years by this time, but I can't find an earlier mention of it on the google.
Note that Alan Sepinwall catches my snap in the comments. In early 2008, he made a similar argument in his column, but he lessens the impact by mentioning that the writers were influenced by Westerns "like The Wild Bunch." In this case, he was wrong. It wasn't Westerns "like" the Wild Bunch, it was The freakin' Wild Bunch that they were paying homage to.
Later, on the House Next Door, I called most of the particulars of Omar's death a few weeks prior to the episode because of parallels between Omar and Pike. I was wrong about one of the specifics: I thought it would be Dookie instead of Kenard. Matt Zoller Seitz still sent me a snow globe for being so damn right. It's right next to me now.