Early name reservation runs 27 October to 3 November for Skyborne Heroic, Skyborne Epic, Warcraft Forever Collection and Collector's Edition accounts. Up to three characters total across all rulesets.
Blizzard also reversed its earlier exclusion of Roleplay-PvP: it is in at launch alongside Normal, PvP and Roleplay. Hardcore comes in winter.
The client is downloadable now; a greyed-out Install button is fixed by restarting Battle.net or switching regions.