Holy crap. How can people be taking seriously the idea that WotC would integrate the two games?
However, as a thought experiment, let us consider what that could entail.
1. Every year, Magic releases a new series of three expansions, called a Block. Each year, the new block is in a new setting, often a setting that is lavishly created and beautifully realized in art and flavor text, much of it handled implicitly so that the gamer's imagination takes over. One possibility is that every year D&D will release a new setting book based on the new block setting for magic, complete with adventures and add-on mini-books.
These campaign settings aren't designed for the long haul. They'll each just last a year, and then the game will move on, developing into something new. Using a planes-hopping model, though, it will be possible to integrate the different settings.
This, I feel, is a [smallcaps]Good Idea[/smallcaps]tm.
2. Some manner of randomization in the rulebooks. Perhaps you could have the core rules, and then books thereafter would have a random set of material.
This, despite my joking of it in the review of D20 College Life, is a stupid idea.