#7 - July 19, 2010, 2:29 a.m.
World of Warcraft "classic" trial accounts are not eligible for the Burning Crusade 10-day free trial, Mitrocraft, but if you have already upgraded your account then you should be able to utilize the provisional Burning Crusade period while playing your account. These two trial periods will not “stack” in the traditional sense, though. The 10-day trial period starts immediately once you activate the free trial in Account Management, and expires after 10 calendar days. I do not believe it will add another 10 days to your remaining 20 free days of play from upgrading your account.