Oh, it's basically an old idea, started with the RAM Kangaroo in WW2, you take a basic tank hull, minus the turret and you turn it into a heavily armoured APC. The Israeli's have a whole series of "Assault" APC's based on modified Centurion hulls, the Nakpadon has extra armour, 4 or so mg's, grenade launchers and I believe, onboard mortars, with room for a small assault infantry squad.
Now, the Russians are doing the same thing with all of those leftover T-55's they have, lying around, cluttering up the place! 8)