Why is this a good thing?

David beat me to it on this one...I had the same reaction when I read this story. (Click the title link for his commentary.)

The next version of Internet Explorer will now offer what has been dubbed, 'porn mode.' Apparently, it's a history-free browsing mode that hides your activity from other users.

From the article:
Although casual users cannot see the previous user’s search history, authorities such as the police will be able to access it if necessary.

So...having no guarantee of privacy from the police is a good thing? By the way, the point of this whole thing has nothing to do with porn use (or the nature of the history you're hiding) but rather the fact that it's automatically presented as a good thing that the 'authorities' can always get the info they want.