Dungeon Master's Basic D&D 5e Rules Released for Free in PDF
It looks like WotC is making separate PDF downloads for the Player and DM parts of the Basic D&D 5e rules.
Whether or not you plan on buying, playing or running 5e, you do owe it to yourself to look at the newest edition of the D&D rules. At the very least, you might find something to houserule into one of the older rule sets you happen to prefer.
As an aside, the Player's rules have been updated to v2.
DM's rules are v1, and include general DM guidelines, monsters and magic items. The core here is the monsters.
The Minotaur for Old-School Essentials
*Requirements:* Minimum STR 9, Minimum CON 9
*Prime Requisite:* STR and CON
*Hit Dice:* 1d10
*Maximum Level:* 8
*Armor:* Leather, including shield...