I think people are really over analyzing "up until now". Yes, in some cases it can mean up to this point and onwards, but there is a reason everyone jumped to the conclusion that it meant Ness was out. Sakurai chose the wording because he knew it would make people instinctively think he has been replaced (don't try to pull any mistranslation crap. It's been explained many times that the English and Japanese are the same). Is it remotely possible that Sakurai is playing mindgames? Well, I suppose so. But personally, I'll give Sakurai enough credit to assume he isn't cruel enough to toy with Ness fans like that. To say that the wording means absolutely nothing is just being naive.
I love Ness, and I did want him to return, but I'm realistic enough to realize the odds are basically zero. However, I can see an upside to him being gone. I can only speak for myself, but it was becoming a little unbearable watching Ness live out the rest of his video game career in Super Smash Bros. Having 4 video game appearances with only 1 of them being in his main game series is a little silly. I think it's good to finally lay him to rest.