I would think (hope!) poppers, as the one size organic has been popular but is pricey and there seems to be a demand for the pocket with snaps. Now Toby can undo velcro on his nappies I've even converted some of my old v2s to poppers so he can wear with just a t-shirt when it is hot.
And the strechy tabs on the v3 leak dye (mine just went onto laundry tabs, but I know one Mum who just has BGs and with washing a whole load of them turned her inserts bluey green
) so maybe some changes to those?
I live in hope of patterns, but patterned PUL is less reliable usually, so doubt it. Maybe gussets like on the flips?