There's an updated branch of DirectHW from PureDarwin  that resolves compilation errors due to Xcode changes. However it doesn't update the packager from packagemaker to pkgbuild and productbuild.
I'm a Mac n00b and didn't get far trying to make it all work, and was curious if there's anyone who would like to take a swing at this. Getting DirectHW updated will also help with other low-level tools. I'd be happy to help test and get patches committed.