I don't think it will be a bad thing, as am sure it will be brilliantly resolved in terms of dynamics, but maybe awkward looking less like the cayenne but will still be odd stretching the 991 looks to a saloon. Also sure it will make porsche lots of money, they are the most profitable car company after all (per car). Also lots of rich people can't fit in in a 911 or by the time they can afford one, need to carry more than one passenger. Aston is also entering the market and bentley made a saloon version of its continental gt recently too. They are becoming a mass market company though with exclusivity diminishing. At the end of the day though, they still make very exciting cars and that is the main point, however, those seeking rarity will have to look elsewhere.