A previous developer started the path to migrating to HTML5 (towards standards compliance) in 7.5.8, we just cleaned it up in 7.5.9 and in the coding for 7.6.0 (with the change to UTF8 vs iso-8859-1). English posts with no special characters (ultimat, etc) can just move over (along with new installs); existing installs that may have extended character sets will have to either set their charset accordingly in the general language file or migrate their data from iso-8859-1 to UTF8.
I believe Isaac talked about a content rebuilder to do the conversion, and I've been using "mb_convert_encoding($fetch["TOPIC_LAST_POSTER_NAME"], "UTF-8", "iso-8859-1")" with my CMS code to pull data and have it display correctly; I'm sure that either way there will be a migration tool (even if I have to write something standalone, using the code bit above).
