It's more of speculation on how the Logan/Parker and Veronica/Piz relationships SHOULD play out. See, I fully and firmly believe that this dual pairing can work, but only if the two couples are portrayed as the following.
Logan/Parker -- clearly using each other as a healing process of sorts. Yes, they should care about one another, but it should be the both of them showing them they ARE capable of having a healthy relationship. For Parker, this helps her beyond the rape and for Logan, it shows him that HE is not the problem which would give him the self-esteem to stand up more for himself in a future relationship with Veronica. Ideally, I'd like to see Logan and Parker mutually decide in ep 18 that while they care about each other, this isn't a long-term thing and they're better as friends.
Veronica/Piz - needs to be the opposite. We need to see Veronica clearly using Piz as proof to herself that she can get/is over Logan, but that really she isn't. We need to see that it's not working, that they don't mesh, because Veronica needs to realize that it's not Logan that caused the downfall of their relationship but her. And maybe I'm still being stupidly optimistic, but the fact that we had Logan tell Veronica multiple times, in multiple episodes, by multiple writers her issues that there will be a payoff. But she won't realize this unless she dates someone light and fluffy and normal and realizes that 'wait a minute! this isn't working.' For Piz, he needs to see that Veronica is just so not for him. In other words, Veronica needs to chew him up and spit him out. And realize that she's done it and that she about did the same to Logan, but that he was able to withstand it and is the only one who can keep her on an even keel ... if she'd just let him.
Whereas L/P should end amicably and nicely, V/P should end badly. The problem is that this not only has to be written and directed this way, it needs to be played this way. Which means, Jason needs to tone down the romantic schmoop in scenes with Julie Gonzalo and show that it's affection and caring, but nowhere near love. And Kristen needs to play a Veronica who is aware of Logan and is either clearly rebounding or is desperately over the top in proving to herself that thing with Piz is great. I can see JD doing this right; La Bell ... yeah, thus the use of the word "problem" above. Her, I don't trust to play it how it should be, or even if this IS the route they're going, how it is intended. Do. Not. Trust. Her. Sigh. Sidenote: I miss her consistently dead-on, awesome, subtext-y, layered performances from S1 so much, it's not even funny!
Anyhoo, if we don't have the above scenarios for both relationships, I don't see how it will be believable with LoVe back together at the end of the season -- and yes, I still think that that's the plan. If they do the above like I said or a close variation, I think it will make the reunion actually work.
ETA: Okay just read Jason's new interview and HE doesn't know (and sounds like he doesn't think) that Logan and Veronica will get back together this season, so I'm pretty sure we can discount anything of significance happening in 16-18. He hasn't seen the last two scripts yet, but there IS a Logan/Veronica scene in 18 that he talks about. Ah, who knows?
And yes, this means I do still have actual delusions of hope where this show and this couple are concerned. Scary, huh?