Is this arrangement permanent in the forseeable future?
Yes.
There are no plans to update the tarballs in ftp://tug.org/tex/ ?
No.
Perhaps they should be marked as obsolete somehow
Good point, I moved them to an archive subdirectory.
(and on CTAN too)...
The ones I checked aren't on CTAN. If you find outdated sources on
CTAN, please let me know.
Thanks,
Karl