Wizards of the Coast revealed at the recent GAMA Trade Show that Time Spiral, launching this October, would be its next block for Magic:  The Gathering.  It will be a three set block, running until late 2007.  Magic:  The Gathering 10th Edition will be the fourth set for 2007.  When Time Spiral launches, the Kamigawa block will be 'out of the Magic environment.'

The company will evaluate the results of its Coldsnap release in 2006, which is not part of the Ravnica block but instead ties into older blocks (see 'Coldsnap -- The Long Lost Ice Age Block'), before deciding whether to do a fourth Magic:  The Gathering set in 2008.