- Simpler
sort.Slice
function. No need to write an interface anymore. - Support for HTTP graceful shutdown.
- Lesser GC pauses.
- Overhead of defer reduced by half.
- Overhead of Cgo calls reduced by more than half.
- Support for using plugins.
- Improvements in race detector for detecting iterate and write to map at same time.
Slides by Dave Cheney which give a nice overview - Go 1.8 Release Party