What I fear the most is the fact that we have absolutely no idea what kind of ending they can pull on us. We knew that something was up with Anders. We knew that Thane would bite the dust eventually. We knew that Morrigan just had to do her thing. But we don't know what they could give us as the resolution for Solas' romance in a DLC.
Solas dies: Could happen, if he is one giant unlucky egg, but would hopefully involve Lavellan staying by his side.
Lavellan dies: Protects him or gets killed by him, I could see either becoming true.
Solas flees yet again: Never say never.
Lavellan has to fight him and seal him away: Also possible.
Ugh. This huuuurts. This will hurt, right?