Is this method still fully compatible with todays current App store downloadable installers? or has a better method been developed to allow installing the Mavericks installer app to USB?
This is better than osxdaily's method (which should only be used for DP1 anyway, not DP4 or the GM):
To make a bootable USB of the GM, use this method:
Your 8 GB USB drive should be called Untitled and formatted as Mac OS Extended (Journaled). The installer should be called Install OS X Mavericks.app and should be in your Applications folder.
Run this in terminal and wait about 20 minutes:
sudo /Applications/Install\ OS\ X\ Mavericks.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install\ OS\ X\ Mavericks.app --nointeraction
You should see something like this:
Erasing Disk: 0%... 10%... 20%... 100%...
Copying installer files to disk...
Copy complete.
Making disk bootable...
Copying boot files...
Copy complete.
Done.
You can then boot up from the USB by holding down the option key, then install the GM from the USB.
This is probably going to be the same for the public release.
Note that this will also install a recovery partition (which osxdaily's method doesn't do).