Fortunately, compared to the corruption bug a few months back that affected stable kernel releases, this new corruption issue isn't nearly as bad. This new issue was only created a few weeks prior with the Linux 3.9 kernel merge window and thus hasn't reached a stable kernel release. Additionally, the issue only affects big endian systems, like some from PowerPC, MIPS, and SPARC.
The commit to "fix big-endian bugs which could cause fs corruptions" was merged on Wednesday with this commit. For those users of EXT4 on big endian systems wishing to learn more about the potential EXT4 corruption issue from Linux 3.9 development kernels, see the EXT4 mailing list.