Lightdarker said:
I'm pretty sure that FFG has followed that formula for all of their other LCGs, so I would imagine LOTR will follow suit.
Core + 6 adventure packs
Khazad Dum + 6 adventure packs
new expansion + 6 adventure packs
wash, rinse, repeat
Core Set + Summons of the Deep AP + Dreamlands AP
Secrets of Arkham (Deluxe) + Yuggoth Contract AP
Order of Silver Twilight (Deluxe) + Rituals of the Order AP + Ancient Relics AP
Then there's the Forgotten Lore AP, including reprints from before the Core Set.
The ratio here is two AP cycles for each deluxe expansion.
Anyway, regarding the number of player cards in the Khazad Dum expansion, I strongly doubt there will be more than four cards per sphere. Adding the two heroes, that would be 50 cards. If there are 10 quest cards, 105 cards will be left to distribute over nine encounter symbols. That's 11-12 cards per symbol. That's close to what the Core Set had: There was an average of 12 cards per symbol.
I guess I came to my "conclusion" solely based upon glancing at the Warhammer Invasion products page (which lists the core set, 3 deluxe expansions, and shows that they are currently on the 4th expansion pack cycle), and the assumptions I've pieced together from this forum and LOTR articles. We'll have to see what it ends up being, but in any case, so long as they're pumping out new cards I'll probably be satisfied.