Ubuntu server version 8.04 (which is currently available in alpha 4, released on February 2 as Hardy Heron) will feautre the 2.6.24 Linux kernel. This will be the first of the major enterprise Linux distributions to be released with the new kernel. Red Hat Enterprise Linux (RHEL) is at 2.6.18 with RHEL version 5.1. Novell SUSE Linux Enterprise (SLE) is at kernel 22.214.171.124 for Novell SLE 10.
Canonical Ltd. has confirmed they will support version 8 of Ubuntu upon its scheduled April release, with the new kernel.