Last year was great! We didn't get to see Aarin and Shiorin most of the time on UST last year, so hopefully we'll able to see them this time through out the ust.
Good thing that they won the ustream award and we see another 24h stream. :)
Shiorin will probably appear more this year since she is out of school. But Aarin still can't appear late at night due to labour law. Her 18th birthday is in June, only one month after this.
I think maybe momomofu wanted to say that there will be a main live and next to it a "special" (as written in the link) one for some moments only. Like last year, when you could watch the girls sleeping (I still feel weird writing this haha) on a link and what was going on in the room with the guests on another. "Sub broadcast", not subbed broadcast.