Willy Tarreau has been the Linux 2.4 kernel maintainer for these infrequent 2.4 kernel updates that largely incorporate bug-fixes and few back-ports, but even he is switching over more of his Linux 2.4 installations to using a long-term-supported Linux 2.6 kernel to the point that he has few 2.4 systems left. As part of his Linux 22.214.171.124 announcement, he has proposed his 2.4 end-of-life plans.
If no critical issues are discovered in the Linux 126.96.36.199 kernel within one year (until September 2011), there will not be a 188.8.131.52 kernel release or any future 2.4 revision. Willy is still accepting 2.4 patches, but unless some critical issue is discovered or other change that would warrant a new kernel update, there is just a year left to switch over to the Linux 2.6 kernel before the 2.4 support goes away for good.
The Linux 2.4 EOL plans are shared in this kernel mailing list message.