Hey,mmlr requested some feedback on the anyboot images at BeGeistert, maybe a little late but here we go: :-)
The DefineBuildProfile comments in MiscRules lack mention of "anyboot- image", and so does the UserBuildConfig.ReadMe file. So it's a little tricky finding out how to build anyboot images yourself.
The anyboot images worked fine under QEMU master, both as -cdrom and as -hda. However naming the image with .iso extension, as suggested, and burning it under OSX v10.5 did not result in a bootable r36474 CD-RW, as tested on three different machines. Does it require special support from the recording software? Or is some manual post-processing necessary? The same revision as cd-image works okay.