Sync Services have been removed in Mavericks, so applications like Outlook 2011 can no longer optionally sync data from the Apple Calendar and Contacts apps. This is a feature I saw very few people use, but it’s worth noting if this is important to you.
Prior to Mavericks, you could connect your iOS device to your Mac via USB, and sync the contacts and calendars using iTunes. This feature has been stripped out of Mavericks. The Info tab in iTunes has been removed, previously used for configuring iOS syncing with your Mac. Additionally Mavericks removes the mail account syncing functionality from iTunes, which provided a quick method of configuring mail accounts on an iOS device that were already configured on the Mac.