I know, that video is amazing!
I don't know if the writers will ever go down this path (although I think they should because it would make for a good romance with the amount of unintentional chemistry they've always had between the two of them), but if anything were to happen how would you see that playing out?
My theory is she should be the instigator because last time he was the one who made it obvious he liked her and now that she's available, I can see him taking the more passive approach and waiting to see if she would make the first move. Because we all know Aria doesn't shy away from showing her interest and Jason's already made his intentions clear, so really if anything were to happen it would have to be from Aria.