The latest round of nightlies includes clickable references in MailNews (
Bug 62033, on by default for newsgroup messages, with a hidden preference for ordinary emails), a better spellchecker (
Bug 319778, HunSpell, replaces MySpell) and the ability to list and disable plugins in the Add-Ons Manager (
Bug 339056, originally a Firefox bug).
Behind the scenes, progress is made towards real page zoom, i.e. zoom including images (
Bug 4821, no UI yet) and making Lightning, the Calendar extension, work with SeaMonkey trunk (
Bug 313822, laying the ground for the actual reintegration).
One item on
KaiRo's Bug Bounty Program, porting Firefox's info bars, seems to be close to finalization (
Bug 270443). Also pending is the port of Firefox's page info (
Bug 379183).