Hi Dirk and Samy

Mutants absolutely.... I am working on something that is a rare derivative of the infection of which more soon. The supplement will therefore be constructed to include (current plan):
infected ragers
infected shamblers
part-developed mutants
fully-developed mutant
ICE troopers
advanced weapons
powered transport
The intention is that players can choose to incorporate all, some or any of the additions.
Thus for The Thing type games, it'd be possible to use the core rules with the supplemental tables for mutants, advanced weapons and transport.
I'm still mulling vampires. They will have much in common with the infected - feeding on the living - albeit without the same degradation in thinking/strength..... so it's possible they'll also be in. Put it this way, I want them to be in.
I previously contemplated and turned against bears, so none planned at the mo, though maybe a polar bear has much in common with the super mutants - feeding on the living - albeit without the spread of virus.... etc.
So, there's much in my head and much on paper....