http://cms.elderscrolls.com/sites/default/files/tes/screenshots/IceWraiths_wLegal.jpg
http://cms.elderscrolls.com/sites/default/files/tes/screenshots/OrcNight.jpg
Don't think that scimitar is glass.
Yes, glass weaponry and armor are very cool ideas and I'm very happy they are returning, and in a very improved form; the bright green glass from Oblivion could get really annoying because it didn't fit in the world, any world, in fact.
For those of you saying it should be different colors: that's cool in theory, but I'd prefer the other colors to show up different sets of armor. For instance, red will probly show up in deadric armor, yellow will be in elvish. As for the other colors, I hope their tinges make their way into other sets of armor. Besides, dark green just looks so cool as a glass weapon. I don't think another color could match it for glass.