What content will be restricted to those without the expansion?
There will be a number of features in The Burning Crusade that will only be available to expansion owners. To name a few: the two new races, the ten new levels of experience (level 60-70), all of the new zones, and the new profession Jewelcrafting.
Will you offer a downloadable option for The Burning Crusade or must you continue to purchase it in stores?
It's very possible that we will allow for a downloadable Burning Crusade at some point in the future, wow power leveling but at this time nothing is definite.
Will there be a Collector's Edition of The Burning Crusade?
Yes, there will be a Collector's Edition package available. For more details on what's included, see our official Collector's Edition page.
Will there eventually be a "combo pack" offered where both the original game and expansion (with the appropriate CD Keys) be offered?
We have no plans to do so at this time, however, it's very possible at some point in the future.
Will the realms be upgraded in time to handle the new surge of players brought about by the expansion?
Yes, as a matter of fact retrofit hardware upgrades designed to improve stability and performance for all World of Warcraft realms will be completed by the time the expansion set ships.