The full spoiler of the Scars of Mirrodin expansion, which will have its prerelease events Sept. 25-26, was released on magicthegathering.com this morning. It went live at midnight delivering over 100 previously unknown cards in the upcoming set.
Spoilers both officially and unofficial have been leaked in the last few weeks, and all 249 cards in the expansion are now available in a sortable spoiler here at ManaNation at http://www.mananation.com/magic-the-gathering-sets/scars-mirrodin-block/scars-mirrodin/scars-mirrodin-spoilers/.
The set features a subtheme of poison counters, in which players with 10 or more poison counters lose the game. The theme was first featured in the Legends expansion in June 1994, and has been periodically revisited in small numbers before its inclusion in Scars.