My Camino install still opens the page http://www.mozilla.org/projects/chimera/ on startup, because this used to be the default home page in the first Camino versions (still called Chimera at the time) and the newer versions have always imported the older versions' preferences. All these years the URL was redircted to caminobrowser.org, now it suddenly throws a 404. If it's not a big deal, please add this nostalgic redirect again. :-)
I don't believe the redirect was removed, but rather we're having some problems with the server. Please check again tomorrow and let me know if you're still seeing this issue.
Things should be working again, but I realized that the existing redirect process was a bit convoluted -- someone going to www.mozilla.org/projects/chimera was sent to the archived Chimera site which sent people to the Camino project page on www.mozilla.org that then sent people to the current Camino site. I just set up a direct redirect for the Chimera page. Please verify that it's working correctly.