Mike Cane tipped me to the following video. It shows the open source version of webOS as it runs on a 2 year old Nook Color. It's the work of a hacker out of Taiwan.
Ping-Hsun Chen compiled the desktop version of Open webOS for his Nook Color. It's actually running on top of Android, not as a stand alone OS, so clearly he used a trick like the ones needed to get Ubuntu running on Android.
This video shows that the work is incomplete and could use a fair amount of optimization, but it's also a beautiful sight for fans of open hardware and open source software. Plus he's running Open webOS on a single core CPU. That's pretty impressive.
Chen has posted his files for anyone who is interested, but they are no where near ready for the average user. (And that goes double for me, given that I keep having trouble with the Nook2Android cards.)