In an official post today, Blizzard Entertainment touched on what players can expect from the "Warlords of Draenor" expansion. The scouting report message included a few specifics on pre-purchasing the title and the free level-90 boost to come with it.
While the expansion has no official release date yet, the new information presented explains that at the time of pre-purchase any Digital Deluxe bonuses will be available "right away." That means the special mount and pet that come with the "Warlords of Draenor" expansion will be in game before it even comes out.
Furthermore, the post goes into the level-90 character boost that will come with a purchase of the expansion. That boost will occur at the time or pre-purcahse rather than players having to wait until the expansion officially launches. Additional boosts to 90 will be available without the purchase of another copy of "Warlords of Draenor" according to the information presented. More details on that, however, will be disclosed later. Players can expect to see developments on the public test realm and the closed beta in the future.