If you need the bleeding edge of a package, install that package from a pinned archive (or similar). If you need the bleeding edge of everything, I don't believe you. If you just want the bleeding edge because 'hey, it feels cool', then you're not the target demographic for ubuntu - something they stated from the outset.
Mandriva had rolling releases with cooker and mageia has also with cauldron. Sorry for looking like a troll but i never got the hype with this ubuntu distro, i wish HN supported mageia more since distrowatch even reports mageia as the number two more popular distro.