Warner Brothers just released a PDF on the Superman Returns production. It includes Cast, Crew, Story... and the details behind them using the Varicam to shoot it. Also mentioned, is how they made it for Imax 3D.
http://rss.warnerbros.com/supermanreturns/archives/Superman%20Returns%20NOTES.pdf

I don't see any mention of the Varicam. I was pretty sure they used the Genesis and that seems to be what they are discussing. A search for Varicam turned up nothing in the PDF. Perhaps you got Panavision and Panasonic confused.


mg

Doh! You got me, it was the Genesis. Page 19.