I think SDL, GTK and Stdio (I'm thinking of Readline/Terminfo here) all have a place in a standard distribution since they are essential I/O-modules for a wide range of applications (though in specific domains).
But I guess this discussion really shouldn't be about specific modules.
I think only whatever is needed to start Hilfe should be in the base distribution (Stdio, sprintf, etc), and everything else should be packed separately.
However it's a good idea with a distribution that contains most of what you need, and a third distribution that contains everything<tm>.
*Especially* things like GTK, Image and SDL should be separated from the main tree, since they are in large projects of their own and should have their own versions and points of release, independent of the main pike version and release cycle.
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