According to the Cryptozoic TCG page on Reign of Fire:
"The Timewalkers have also uncovered time-lost relics from the past. These treasures have returned, featuring every Loot Card™ that has ever existed in the World of Warcraft Trading Card Game! With better chances to open Loot cards in each pack, players will be able to uncover some of Azeroth's greatest trinkets and treasures!"Yes, you read that right. Reign of Fire will have EVERY loot card every created for WoW TCG. Each box will have a chance to yield something from a previous expansion; "15 game cards per pack; 36 packs per box".
This blows my mind and is very tempting. The only problem is that it's a risk to purchase an entire box, since there's no guarantee that you'll find a specific loot card you're after. On the other hand, it's also a risk to purchase a specific loot card from Ebay or other sources, albeit a smaller risk.
I'm unsure how much an entire box will cost, but if it's cheaper than an Ethereal Trader or Dragon Kite from Ebay, I may just save up for one. Reign of Fire TCG expansion is set to be released July 23, 2013.