Basically, we discovered that we could pretty easily add cross-realm browsing to the Raid Browser for 5.4 content, so we've done that in 5.4.2.Ħ.0's Group Finder is an entirely different thing being built from scratch. This is totally unrelated to the new Group Finder we announced at Blizzcon. One is the cross-realm functionality being added to our existing Raid Browser in patch 5.4.2. There are two completely separate developments going on here. Since we're still seeing some confusion about the Group Finder, let me try to clear up what I can:
Official Community > General Discussion forum (US).