Apple has quietly replaced iTunes 9.1.1 with iTunes 9.1.1.12. The new release fixes an issue we reported on earlier this week, in which 128 kbps conversion occurs on every sync, meaning that several unchanged songs are needlessly converted and synchronized every time the sync process occurs, resulting in inordinately long sync times.
Unfortunately, the new release is not available (as of yet) through Software Update. To apply the update, you must re-download the new iTunes 9.1.1 installer (which is now version 9.1.1.12) and reinstall it.