[XeTeX] No Non-English Hyphenation

[Karl Berry]

    Don't ask me why xetex and xelatex look for files in totally
    different folders

They don't.  That is, the search path/algorithm is not specific to any
particular engine.

    $ kpsewhere -engine=xelatex xelatex.fmt	// where the new ones ended up
    /home/sebastian/.texlive2008/texmf-var/web2c/xelatex/xelatex.fmt

I have never seen web2c/xelatex/xelatex.fmt before.  It would ordinarily
be web2c/xetex/xelatex.fmt, since the engine is xetex, not xelatex.
That's how the distributed fmtutil.cnf sets things up.  (Likewise for
pdftex/pdflatex, etc.)

By the way, you can discover all occurrences of a .fmt, regardless of
the engine name used, with, e.g.:
kpsewhich --engine=/ --all xelatex.fmt

I sometimes find that helpful for figuring out these sorts of problems.

karl