Seems like many people are interested in drysuits this month.
Hopefully I can troll for discussion about breathable fabrics.

Kokatat still uses Goretex in most of their drysuits, except
a semi-drysuit with Tropos. I don't know if they have switched
their high-end drysuits to Goretex XCR yet.

OS Systems uses Sympatex, a German 3-layer fabric with a layer
of hydrophilic copolyetherester.

Palm/MTI uses XP100, XP150, and XP200 depending on garment.
All are layered with hydrophilic polyurethane.

The '06 NRS Extreme drysuit uses TriTon fabric, whatever that is.

Here is an interesting summary of US Army research on various
waterproof/breathable fabrics:
http://verber.com/mark/outdoors/gear/breathability.pdf

I want a drysuit made of eVENT!