I just finished testing an upgrade to MacOSX 10.4 on my desktop system. I'd been running a previous build, and all was working fine, but I hadn't thought to install WebObjects - it always just breaks a bit with Big Updates, until they release a point-oh release for WO. I just finished installing 10.4, XCode 2, WO (5.2, 5.2.2, and 5.2.3), and Subversion. Checked out the APOLLO/Pachyderm source tree, and build and ran Pachyderm2.woa.
I did an "Erase and Install" of MacOSX. It's always safest, and it's probably not a bad idea to periodically cast off any kruft that accumulates over the year. Little utilities that get installed and never used. Libraries that sound cool, but never get used... If anything gets overlooked, it's pretty trivial to install stuff...
All seems fine. I'm sure there will be some little niggles that get me, but it's working well enough to use, and is enough better than 10.3 to justify any small hassles that pop up (jinx).
As part of the process, I recompiled the APOLLO/Pachyderm installers for MacOSX to ease migration of any developers to a fresh Tiger install...
Now, to boot my Powerbook into Firewire Target Disk Mode to move a copy of ~/dnorman onto a backup drive on my desktop box, so I can install Tiger on the Powerbook while I'm working...