Love it or hate it Ubuntu is the most popular Linux distribution to date. While we at The Linux Experiment have not included it amongst our chosen distributions, many of us have had experience with it in the past and look forward to seeing the new features that have been lovingly baked into this release.
Congrats to Canonical et al. for delivering Karmic Koala, hopefully another great version of their staple distribution.
Previously I was running KDE 4.3.3 on top of Fedora 11 (for the first experiment) and KDE 4.6.5 on top of Gentoo (for the second experiment).