Warning: HEAD might be broken! I am "landing" the performance patchseries into HEAD, and while it got quite a bit of testing, it's 180 commits,
35 files changed, 3062 insertions(+), 1896 deletions(-).
New installs should Just Work. That should not be a problem.
Upgrades are a bit trickier... after doing cvs update, hit /admin to trigger it and it will work. If you try to load the homepage, it will only work if you are _already_ logged in as administrator. Else -- it'll show errors due to the changes in accesslib.