The updates will bring a slew of performance and bug fixes.
iBooks 1.0.1 “includes bug fixes and improvements to performance and stability.” Safari's updates are unknown; however, the version is labeled 7.0.1. Remote Desktop Client 3.7.1 is “recommended for all Apple Remote Desktop clients and addresses several issues related to overall reliability, usability, and compatibility.”
As previously reported, the Mail update "improves stability and compatibility with Gmail, and includes fixes for users with custom Gmail settings." The site has learned the update will be a standalone one called "Mail Update for Mavericks 1.0".
The updates are being tested internally and should roll out to users soon.