I know nothing about the internals of any of the Ruby VM's so this may be a totally stupid question ...

How hard would be it be to 'marshal out' the entire running Ruby VM to a binary image and load it back in again like the way the Smalltalk VMs seem to do, or add the ability to marshal out objects as a memory image of some sort, meaning they can be marshalled out and in really efficiently (ie stuff a true Ruby object into Memcached instead of a string representation of it ...