lots of small things
silent cron monitoring
2GB memory limit
improved style.css & visual style in general
not using MyISAM but InnoDB everywhere
fulltext search disabled (use Sphinx for that)
stat charts are generated with a better font (support for european diacritic characters)
the way dates are displayed is fixed
automatic notification to the sender is optional
added a customer backend class that will reopen a issue if already exists from a sender
possibility to turn off drafts, comments, etc. from the issue view
added the new configuration settings