I'm 110% fine with Laurel dying, but I also 110% predict she won't, because the producers seem determined to not budge from the comics canon of Dinah Laurel Lance becoming Black Canary (which, as I'm pretty sure I've said before, is annoying because they haven't felt the need to hew closely to comics canon on other things). (And I say that as someone who LOVES Black Canary in the comics and loves the Green Arrow/Black Canary relationship. But those are pretty damn different characters than the ones we have on TV. So let them be different, and stop pushing Laurel as the future Black Canary. Ugh.)
I'm guessing that Diggle, Felicity, Thea, and Roy survive. Although I kind of think Thea will join forces with Merlyn. Which would ROCK.
I really feel like a Lance is going to die, and I'm afraid it's going to be Cop Daddy, because he just got his detective badge back, and what's a bigger cliche than killing him at this point? Plus the show has already fridged 2 major female characters this season, and I want to believe they won't kill a third (Sara), which leaves Cop Daddy.
OTOH, the show has been telegraphing HARD that Sara's going to die. And given that Sebastian (R.I.P.) said Slade will go after whoever Ollie loves most, I suspect Slade will go after Laurel, and Sara will sacrifice herself to save Laurel. (In which case, NO KILLING OF COP DADDY.)
Merlyn won't die. I'm not spoiled, but I think the show knows what a goldmine they have in Barrowman.
I'm torn on Slade. I feel like he needs to die, but I hate to waste such a damn fine character. Plus, Manu Bennett. Maybe he can get cured and go away and become un-crazy.
[Sidebar: I feel about Slade how I feel about Beaver in Veronica Mars -- I *hated* what the show did to Beaver in the second season. HATED it. Because I liked him, and liked how he had developed. But that's the point, right? That's what makes it so much worse, that a character you liked (and maybe I'm the only one who liked Beaver right up until the point we found out he was fucked WAY up, but I really *did* like him) ends up being the bad guy. Anyway, I absolutely loved the S1 flashback friendship between Ollie and Slade on the island. LOVED. And yet when Slade Wilson is introduced, you know he has to become Deathstroke. And that absolutely KILLS me. Because I really liked Slade on the island. And I hate that he's the crazy bad guy now. Except Manu Bennett is so damn good at it.]
Isabel is probably going to die, which is okay, except, like I said above, I'm tired of women on this show getting killed. Except she's bad. Oh! Maybe she'll just lose an eye and then she and Slade can run off together and be crazy!
And here is my prediction for the final flashback of the show: Amanda Waller shows up to "rescue" Ollie from the freighter (or island, if somehow he ends up back on the island), only it's not an oh-thank-god-I'm-saved rescue, but an oh-shit-what-fresh-hell-has-my-life-become "rescue". Because the show has to address whatever backstory is between them, so I expect them to set it up for next season.