I thought the season ending was great; I mean, I got pissed the first time, but I watched it a few more times and really enjoyed it. Rick has been such a cocky dickhead since he got out of Terminus, watching the horror slowly dawn on him that he wasn't at the top anymore was just great. And Trevor Phillips, leading the man to his downfall, awesome.
Whoever died, the repercussions of that, wouldn't have helped the story they were telling in that episode any. It will when they start the next season, so keeping it under wraps wasn't a huge deal. I'm OK with it, I just don't want that to become a habit.
As far as who it was; my vote goes to Eugene. If not him, then poor Rosita. Both of them are at points in their story arcs where they are completely expendable. Eugene got them to Virginia, he gave Rick the info on the ammunition, and Abraham knew where to go as well. He is unattached, and completely expendable. Rosita, likewise, has no noticeable upswing at this point, is no longer attached to Abraham, and becomes expendable; gives additional fodder to next season in that Tara's connections with the community are severed, and so would Spencer's, makes two more expendables next season.
As far as Abraham being the one to get it; I don't think they could do that, when they just spent a whole season pulling Sasha back from the brink of insanity.[/code]