Now All Engines Treat Underscores as Word Separators

[Halfdeck]

Seems that we'll be seeing a huge change in search results if that's the case.

Keywords in urls don't really impact ranking all that much, especially for high traffic queries, where high level of competition marginalizes on-page factors. So for terms like "free porn", this change would have no effect, though you might see slight movement for terms like "mary had a little lamb for dinner last night."

Though all long tails combined is a bigger percentage of Google's overall traffic than head queries, most webmasters don't track their long tail SERP positions, so I think Google expects any changes would go unnoticed.