Nice read. Here are some personal observations.
1) Gore-Tex
For breathable waterproofing, nothing (yet) beats Gore-Tex. I've wished for years that is weren't so, but there's a reason they ask for (and get) a premium, and why for manufacturers from The North Face to LL Bean, their top tier items that claim waterproofing are all Gore Tex.
2) Fabric Weave
While a very comprehensive list of performance fabrics, there's also something to be said for the specific weave of said material.
Nike, for example, in some of their heavy duty winter run gear, has a very rugged, almost brick-like (5-6mm) waffle pattern for the material, which seems to be very effective at creating air pockets that retain heat yet still breathe. I love this stuff for near/sub zero adventures.
3) Wool
Wool hasn't given up the ghost. In addition to Smartwool, who makes soft and non-itchy socks and such, wool nowadays can be lightweight, breathable, washable, and typically less stinky than synthetic counterparts.
4) Layering
I think the layering recommendations are spot on. That flexibility makes winter activities much more bearable. Even more flexible are outerwear pieces that increasingly are incorporating hidden vents, zippers, and varied materials in offering increased insulation in some areas (torso) while less in others (armpits, etc...).