They struggled trying to keep the betas in control. Inclusion of too new , latest technologies caused breakage and other problems to Ubuntu 8.04 Hardy Heron.
Harald Hoyer wrote a good comment out of the responses to Mark Shuttleworth's post about synchronizing distro releases.
Ubuntu should stay as they are. Its a good distro for me to recommend for those users who just want a JustWorks machine with no interest to contribute to FOSS world. Fedora development is admittedly way too fast for those type of users to bother. If Ubuntu tries to follow Fedora rapidness, that won't solve anything (except, maybe, open a way for grabbing the Fedora contributor/userbase to the Ubuntu side). Ubuntu has been a good player in trying to solve their bug #1. So, keep it that way. The Fedora path is too hostile for Ubuntu current target market.