The April 1st playtest package was the same as the previous package, except for the addition of the Mines of Madness adventure and revised pre-generated characters.
This playtest packet included:
Playtest Packet (2013-04-01)
D&D Next Playtest Update ("Read First", 3 pages)
How to Play (25 pages)
Creating a Character (5 pages)
Classes (49 pages)
Races (8 pages)
Backgrounds and Skills (6 pages)
Specialties and Feats (14 pages)
Spells (50 pages)
Equipment (11 pages)
DM Guidelines (23 pages)
Bestiary (91 pages)
Magic Items (31 pages)
Character sheet (not updated, 2 pages)
Dungeon Module B2: The Caves of Chaos (not updated, 23 pages)
Dungeon Adventure X1: The Isle of Dread (not updated, 44 pages)
Reclaiming Blingdenstone (not updated, 40 pages)
The Mud Sorcerer's Tomb (not updated, 34 pages)
Conversion Notes: Against the Cult of Chaos (not updated, 19 pages)
Conversion Notes: Storm over Neverwinter (21 pages)
Mines of Madness (47 pages)
Pre-gen: Dwarf Fighter (1 page)
Pre-gen: Dwarf Paladin (2 pages)
Pre-gen: Elf Ranger (2 pages)
Pre-gen: Elf Wizard (2 pages)
Pre-gen: Halfling Rogue (1 page)
Pre-gen: Human Cleric (2 pages)