Is John 7:53-8:11 even scripture?

"A person hearing these words should recognize that they have no authority as authentic words of Jesus," he said. Christians who are reading the story, he said, should give it the same authority as any other unsubstantiated early Christian teaching about Jesus."
- DTS Professor Daniel Wallace on John 7:53-8:11
I read this article over at Christianity Today and was shocked this was the conclusion drawn.

Basically the article is about how, as my ESV puts it, "[The earliest manuscripts do not include John 7:53–8:11]," and how most lay Christians who read this will just assume they were placed in the Bible or accepted by the translators because they have some merit.

Admittedly this is the position I took/take. I assume someone along the lines thought it important enough to be included, and lean towards to the view presented by another professor:
"There is no reason to pull this out," said Craig Evans, a professor at Acadia Divinity School. "Nothing about it says Jesus didn't have this encounter." All of the stories about Jesus began orally — it was a few decades before they were written down — so it is possible that this story just did not get written down until much later, Evans said."
I've heard this section of the scripture be disputed in the past but until I know more about it I assume I'll continue to read this as the words of Christ.

I tend to think when it says "all scripture is breathed out by God," that God had some idea what the Bible ending up in our hands would look like, he knew this would be in, it is compatible with other teachings by Christ and probably should be taken as equal to the rest of the scripture. Take a gander, its not a long article, and quite fascinating.

Edit (4/28/08): This has been carried on here by Tim Ricchuiti, and here by me.