KEF is ideally placed as a hub and I would expect it to continue as such (although the infrastructure is getting tight). Whether it makes sense to operate two brands along side each other is questionable. You want to maximise the number of available connections which points to there being a single operator, although there is no reason why there can't be a WOW style low cost section in each aircraft. Then again Qantas & Jetstar operate as separate brands and I believe codeshare. Makes life confusing for the punter though.