I just read
this very interesting piece as well as its two follow-up pages
1 and
2.
Following Johns advice, I deleted my font cache files, namely /System/Library/Caches/fontTablesAnnex . My login (after a restart) went down from at least 3 minutes of spinning disk activity to maybe 15 seconds; without changing anything in my font setup (managed by Font Agent Pro), the fontTablesAnnex file went from 77MB to 788 kB.
Until Apple fixes the problem, this is one for my DT collection of trouble-shooting tips.
Highly recommended; thanks a lot John!
((Sorry, this should have gone into MacOS ))