Spaceweather seems to be the only site that has the actual SOHO video composite showing perihelion, which is quite remarkable:
I was watching the NASA Channel yesterday and they said the composition of much of the comet is like “a well-packed snowbank”...not something that has real mass, except at the core, perhaps. And it passed something much closer to the sun than anything we know of.
So it seems that ISON is simply full of surprises!