Unlikely. On the one hand, Apple wants to control software in the app store to preserve their market position (hence the ban on apps that significantly duplicate Apple's own apps) and Apple's image (hence the controls on user interface and on content like sex).
However, the success of any platform depends on people finding what they want, and that often means iPhoto workalikes and porn. Attempting to control consumer electronics devices like the iPhone is one thing; trying to control the way a desktop general-purpose computer is another.
America Online succeeded in large part because of the sex chat rooms. The Mac succeeds in large part because of the huge library of apps that includes things that Apple doesn't like, from user interface modifications like WindowShade to sex games to browsers like Firefox.
From a benefit standpoint, Apple's greatest gain is a huge and successful, but tightly controlled, app store that promotes popular software in one place and also offers Apple a steady revenue stream, while at the same time also encouraging a thriving software ecosystem that offers owners alternate ways to get software that Apple doesn't want to make available in the App Store. I think it'd actually work against Apple to try to control the desktop systems more.
But then again, Apple *did* make the hockey puck mouse, so sometimes they do foolish things...
