This must have slipped under our radar back in March, but iConcertCal, the both clever and useful iTunes plug-in that scans your artists to find local concert dates, has updated to v1.2. In addition to "greatly improved" concert listings in both the US and UK, iConcertCal can now export calendars to an iCal format (note: this isn't exactly 'iCal syncing.' Hopefully that's on its way). For those shows that might still slip through iConcertCal's fingers, the plug-in allows you to edit its calendar and add shows you just gotta keep track of.
Also on the list of changes is the ability to chose which iTunes library to monitor for artists and show dates, an "easy way" to list shows from artists that aren't in your library and city + date venue info now placed in the header information. Amazingly, iConcertCal is still free and available for both Mac OS X and Windows.