- x32 ABI
- C11 ISO Standard
- Removal of Linux Kernel 2.4. The minimum requirement has been raised to Linux Kernel 2.6
Slackware 14 will not be shipping glibc as part of it's supported application. Instead, they will go with patched glibc 2.15 which is proven to be stable enough after several patches goes into the stabilization process.
Besides, Slackware is going to be released based on Linux Kernel 3.2.x, which hasn't supported x32 ABI as well (it's officially supported since Linux Kernel 3.4), so there's no point of including this glibc version to Slackware for now. Future Slackware releases might be based on glibc 2.16 (or newer version) though.