This is a project we've always dreamt about doing, something all of PI have been involved in, not just the PDS developers.
Wait, here's a plot twist: We don't get one but TWO new IP's announced at gamescon!
Well it is kind of surprising to create a hint singeling out one of the several options in order to say it's not that one. Especially by doing it by focussing on one small aspect of that game just like the did with EUIV the other way around.
It's a game. stellarisgame.com was registered 25-jun-2015.
At this point, if there is no denial from Paradox about the Stellaris speculation, it seems pretty obvious that it will be augustus... another space game in an already saturated market, while there is no good ancient age strategy games except the TW and a few city builders... I'm going to sound selfish and cynical, but I hope that Stellaris will be a commercial failure so that Paradox goes back to grand strategy historical games.
Maybe they got it, there was something about talking with Martin or his people about it in some stream a few months back