Phase one is done!
The initial phase of re-working the portal component of my site is done; I've deployed an updated Jetspeed-based portal with a custom-built skin that, in general, matches the Currency skin provided with roller.
I've also successfully converted the database behind Jetspeed from Oracle to MySQL. This was a larger pain than I expected because the Jetspeed 1.5 scripts for MySQL don't work with MySQL 4.0 (the latest version). I got the scripts from the current source tree, which almost worked. I also built the PSML database scripts for MySQL manually, because it was faster than figuring out how to get Torque to generate them.
I've also successfully isolated ALL of the customizations I've done to the default Jetspeed 1.5 distribution now, so that upgrading to 1.6 should be much easier than going from 1.4 to 1.5 was.
Next up: Add the ability to remove files from the default distribution when building a customized portal using the Jetspeed Maven plugin. Then I can get rid of a bunch of cruft that comes with the distribution. Hooray!