The next release of the Ubuntu Linux distribution, 9.04 (Jaunty Jackalope), contrary to expectations, will not ship with the Linux 2.6.29 kernel, which is currently at release candidate stage.
Although it is expected that 2.6.29 will be ready by Ubuntu 9.04's release, Canonical's Tim Gardner has said "Jaunty will absolutely, positively, and without a doubt, release with a 2.6.28 kernel. Is that clear enough to dispel all rumors?". Phoronix reported some disappointment with the decision, since Jaunty Jackalope will therefore have no mainline support for Btrfs and Intel kernel mode setting.
http://www.linuxlinks.com/portal/news/article.php?story=20090212140739423