I've read a few bits of chatter along the lines of "Why don't IV port Defcon to <insert random mobile platform here>?"
It seems to me, at least - if IV aren't interested in porting Defcon, that must be because they're unlikely to generate enough income from the port to make it worthwhile. Simple economics.
I also know that there are some lucky people out there who acquired the source code via the Humble Bundle (the sale was long finished before I found out about it

It's a purely academic question at the moment - perhaps impossible/unworkable due to license restrictions, accountancy restrictions, technical feasibility restrictions, or whatever. Discuss, anyone?
It would certainly be interesting to work on adapting Defcon for touchscreen or PS3/XBOX/Wii controller. Getting different ports to all communicate to allow cross-platform PvP could get hairy too. It might generate a whole new set of debates in the community - never mind "SA v EU who wins?" how about "PC v DSi who wins?"
<shields up>
<prepare for xander-esque slapdown>

SpitJock (sig. pending)