Wez Furlong posts today about a response made to a previous mention of "PHP vs. ASP.NET" in this article from Joe Stagner in this post on his MSDN blog.
From Wez:
Joe's response is perhaps a little pro-Microsoft (you can't really blame him for that--he does work there :-) but the essence of his response rings true; there's nowhere near enough factual data in the OTN article to make a balanced decision one way or the other.
To be fair to Sean (the author of the OTN article), it does say "Opinion" across the top of the page and the byline is "One developer's view of the pros and cons of the two most popular means of building web applications", but it's easy to forget those once you're into the article.
Wez also mentions one of his personal views on the whole debate, basically saying that even if PHP is the faster/more efficient, some situations might do better with an ASP.NET solution (what's the cost of implementation?).