Judging from the pattern and info given, a decent prediction can be made on the LIs.
I believe that it was stated somewhere that there would be eight LIs (?). Cullen, Sera, Cassandra, Josephine, and Dorian are the ones that have been confirmed so far.
This kind of implies that Vivienne is romanceable, and The Iron Bull has been pretty heavily teased to be romanceable.
So far there has been a warrior, mage, rogue, and advisor as LIs for each gender. So assuming each gender has an equal amount of LIs:
Female:
- Warrior: Cassandra
- Mage: Vivienne
- Rogue: Sera
- Advisor: Josephine
Male:
- Warrior: Iron Bull
- Mage: Dorian
- Rogue: ???
- Advisor: Cullen
This implies that the last LI is a rogue, which leaves Varric and Cole. I don't know how valid this information is, but I've heard someone say that two of the LIs are race-gated (don't know the source for this info). Assuming this is true, this makes me think that the two race-gated LIs are The Iron Bull, and Varric. Presumably they're race-gated because their sizes would require new cinematics for different races.
It'd be nice if Varric is romanceable; kind of wanted Blackwall to be romanceable though. Alas. 
Of course, this is just a prediction based on some patterns. :>