Here are my notes now that patch 4.1 is out.
1) Perfect green Cataclysm gems vendor for 90 silver. Cut green Cataclysm gems vendor for 75 silver. Uncut green Cataclysm gems vendor for 5 gold.
2) Obsidium Ore floor price is now 30 gold a stack. Elementium floor price is about 27.25-27.5 gold a stack.
3) New glyph: Glyph of Frostarmor is learned from Northrend Inscription Research.
4) Horde JC daily quest giver has moved inside the building.
5) It now costs 1 Blackfallow Ink to craft 3 Dust of Disappearance.
6) Adventurer's Journal now has a 1 hour cooldown and Forged Documents now cost 1 Blackfallow Ink to craft. (Both tips come from Alto @ Alto's Goldish Advice)
7) Level 75 can now max all out professions. Trainers in cities will teach you the Twilight Highlands recipes (meaning no more reason to level to 84 for some professions). (Tip from Consortium forums).
This post will be updated as new discoveries are made.