Exactly. The Lustria and Storm of Chaos sublists, and the units and magic items from the Dark Shadows (Albion) campaign WERE official, and have generally been accepted in most tournaments and groups. However, as those lists have aged and the books fallen out of print,
GW has (to some extent) been phasing them out.
GW's kind of been of (at least) two minds about it, however.
The extra magic items and special sublists, have generally been seen as being lost when the army in question has gotten a new book, unless said book had the list or item added to it. The major exceptions to this have been two of the new units (Goblin Hewer and Hellcannon), and the Dwarf Slayer Army, which actually got an update in the main official
GW Dwarf
FAQ actually the current Dwarf book came out:
http://us.games-workshop.com/errata/assets/dwarfs.pdf
The
UK GTs started banning Storm of Chaos lists either last year or the year before. The US ones have allowed them up through last year, though this year the rules (just recently released) are much stricter. Even core armies which don't have books yet (like Dogs of War and Chaos Dwarfs) are not allowed.
http://gt.us.games-workshop.com/2008/gt_promo/rules_wh.htm
The Independent
GTs in the US (and some of the ones in the
UK, from what I understand), on the other hand, do usually allow Storm of Chaos lists,
DoW, and Chaos Dwarfs. I'm less sure about Lustria. The Storm of Chaos lists are most commonly phased out/disallowed when the main army they're built from gets a new book, as the points values are often in conflict, and there may be other incompatibilities between the list and the new book. It's always best to check with the organizer, but I know that they usually prefer to let people use the expensive armies they built which haven't been superceded by updated army books, especially the ones from Storm of Chaos, which
GW originally told us was fully official and appropriate for tournaments.