I don't think they're so much forcing Orion and Wonder Woman on anyone rather just adding some conflict to the mix. I still don't forsee them ending the Superman and Wonder Woman relationship anytime soon though. Knowing the douchey way Azzarello is writing Orion (seems like no one can get the loveable rogue character right these days; they never turn out like Han Solo, rather just a douchebag bad boy), I'm guessing in #19 he's just going to steal a kiss or something.
In any case I see it developing as a classic case of mutual jealousy. Diana will probably be jealous of Lois to some degree, and Superman will be jealous of Orion.