For the record, Phil stated over and over that you could use the launcher of your choice, and that he didn't understand why people get so upset over Touchwiz.
Here is/was the confusion: at the time of the pre-release review, the method of replacing TouchWiz was unclear:
1) Run launcher of your choice. Yes, it replaces or runs on top of Touchwiz, but TW is still running in the background. This is a system hog on slower handhelds and no one knew if it'd be a problem on the Epic.
2) Kill TW and change the default. Like in the posted video (thank you for the link). It was unclear if that method was available on the pre-release demo units that journalists got their hands on.
What is still unclear from the posted video is whether or not this method sticks after a reboot, and if it will still be around after the first update. Also still unclear is if we'll need root to remove TW or make the configuration change survive a reboot.
Still, very good news and thanks for sharing. Monkeying with launchers is my second-favorite thing to do behind monkeying with task killers.
--Qfg