If you look at the git site for jQuery 1.8 you will see that they are breaking the core jQuery code in separate modules so that you can do a custom build, based on what you need.
What this means is that you will be able to reduce the download size of the current 93k for the min.js version and exclude the “modules” you do not need.
Want a lighter weight jQuery 1.8? You can have it !
Starting in jQuery 1.8, special builds can now be created that optionally exclude or include any of the following modules: