Update from product development session at DDXP this afternoon (tweeted by Dave Chalker @ critical-hits.com):
"Gamma World. Uses D&D rules. Complete game experience in box. 160 rulebook included. Rooted in d&d. Chargen, how to GM, monsters. 10 encounters, poster map, tokens. New card mechanics. Character will be mutant. "part cockroach, part yeti" In GW starter box, item cards and mutation cards that come up randomly. Some powerful, some silly. GW will have booster cards for players. GW booster packs will be random, only found in hobby stores (not bookstore) Will also have game day."
Interpret that as you will.
Full Twitter feed on D&D announcements he tweeted today:
Gato, CH News Robot (criticalhits) on Twitter