Do we reckon the show will follow the comics and it'll be Negan who kills Alpha? It would sort of play into this redemption arc he's got going on... and with Michonne leaving but (presumably) Judith not leaving, maybe Alpha in some way threatens Judith and Negan sees himself as her new protector . I believe in the comics, Alpha's death is what sparks the Whisperer war lead by Beta and it's eventually Aaron that shoots and kills Beta - but in the show I think it's a safe bet that it'll be a crossbow bolt from Daryl.
Also, I think in the comics, Beta kills Andrea whose role in the show has been filled by Michonne sooo... .
Spoiler:
Negan killing Alpha would be so disappointing. Now them flipping it and having her kill him would be glorious but that's not happening I think Carol as Alpha's killer would be better, and nicely foreshadowed in the latest ep when Alpha said she can't wait to meet her.
Wasn't Andrea bit? I haven't read that far but I keep up with the general gist online but I'm sure I read she got bit and killed herself, quite like her TV counterpart if so