Hi everyone! The original poster, Urdadinatoaster, was posting on my behalf. Said iMacs and their kernel panics are mine.

I don't have any of the software in question running, just anything that Netflix or possibly Hulu could installed and/or updated recently without my knowing. The iMac with constant panics upon boot DID have new RAM installed in December, but I've swapped back to the original ram with no change. HOWEVER...

The only piece of hardware that I could think of all 3 machines sharing is my wireless router. I booted super-bad iMac into safe mode, and before a panic could hit, disabled AirPort. It seems to be running just fine. Hmmm....

I'm going to update the firmware on my router as soon as I'm done typing this email. I'd be happy to copy and paste any of the many panic reports found in /Library/Logs/DiagnosticReports if that'd help anyone deduce things for me.