I have no experience at all with Gamma World. How does/did it differ from being the D&D rules in a different setting?
I'm pretty confused on how the cards are intended to be used because I am not familiar with how the game is meant to be played.
I've read a few online blogs & articles and this is what I've gathered:
1) The new GW is going to be compatible with 4e. So you can use all your 4e stuff with your GW game and vice versa...supposedly.
However, the GW heroes will deliver more damage and have less healing.
2) There will be two sets of cards - Mutations and Tech. Tech will be very disposable, aka you can use it until it breaks. The Mutations will be random and when you roll a 1 when using a mutation, you exchange out that mutation for a new random one. Thus, the cards are part of the play experience.
So PC death will be common, thus more chargen. Tech will come and go faster than magic items and Powers can change during the same game session.
3) The theme appears to be Wacky & Deadly which is fine because most people played GW that way in the past. Of course, its a fine line between Gonzo and Silly on the Wacky-meter.
Of course, the DM can always focus the game by limiting chargen options to those less silly.
4) The drive for cards, maps and game bits is being driven by Hasbro's fear of pirates and downloaders. Like WFRP 3e, the hope is the physical components will drive purchases. This may work fine since most boardgame companies are giving the rules away for free and you don't see people online talking about creating their own boards. The amount of time it would take to scan, print and laminate the GW cards and the effort involved is more than most pirates will spend.
5) The booster aspect is going to be huge. My CCG buddies call it "cardboard crack" and RPGers just need to look at their shelves for the number of splatbooks they buy.