I love the Innsmouth Horror and I cant wait for the next expansion. From the trend, the next expansion will just be a small box. I'd love to see a Mi-Go centric expansion. Or even the Yithians. 
A cool idea for the next expansion
The CoC LCG has gotten mileage out of the idea of having multiple different cards for different monsters and having bonuses for those monsters apply to all the cards. By that I mean that the LCG has a Gug, a Slavering Gug, a Monstrous Gug and more. And any card that referes to a Gug applies to them all. Just like the two pseudo-cultists in the BGotW expansion.
I think there is a lot of possibility to epxand on that in a small box expansion. For example, bring out new monsters who count as Dark Young and then bring out more cards that refer specifically to Dark Young - even weapons that could gain a bonus against them, etc.
One small box expansion could easily bring out half a dozen new Heralds, each of which refered to a different type of monster, and new versions of those monsters.
I would love to see an expansion which will bring more power to Nyarlathotep as an AO. For me he is too weak, according to his name.
Box could contain a lot of Mask monsters, and a lot of heralds - avatars of Nyarlathotep. Hey, maybe herald for every mask monster - according to ancient one who has 1000 faces!!! Yeah!
Sigismond said:
I would love to see an expansion which will bring more power to Nyarlathotep as an AO. For me he is too weak, according to his name.
Box could contain a lot of Mask monsters, and a lot of heralds - avatars of Nyarlathotep. Hey, maybe herald for every mask monster - according to ancient one who has 1000 faces!!! Yeah!
Ooooo! I *love* this idea!
I think the next expansion should indeed be a herald-based one, with lots of new official heralds that make the game harder, not just for Nyarlathotep, but for other weaker Ancient Ones as well. Plus the two online-only heralds finally printed on cardstock. I don't want anymore boards, cards or tokens - just heralds, and possibly a couple of guardians as well. And I don't like printing my own game components, thank you.
-Villain
As long as the next expansion include furniture big enough to hold all the expansions. Perhaps something in a multi-level affair.
Perhaps something designed to decrease the impact of the HUGE number of cards has on the amount of space needed to hold it all. 
Seriously, one of HPL's main areas of writing was involved in his Dreamlands/Fantasy area. Perhaps changing the Dreamlands OWE into a gate to another board? This would be an alternate linking world to the other OWE areas.