Well, the event is apparently official. It's the contents that are rumored…
It's been a little while since Google announced new Android phones, almost a year in fact. Two phones have been rumored this year, which are allegedly named the Nexus 5X and the Nexus 6P. I am not sure how much of the leaks are pure speculation, versus grounded in actual fact, so I will leave it as an exercise to you to read a couple of links that summarize them. A grain of salt will be necessary of course. It's not that we are afraid to look at rumors, as we do so frequently, but I'd rather not play arbitrator this time. I don't think that I can research this topic enough to arrive at a sufficient level of confidence at the moment.
What I can say is that Google will host an event on September 29th, 2015, to announce whatever they have. The invitations have gone out to sites like CNet and it will present devices that use Android 6.0 M, which Google announced stands for “Marshmallow” last August. An updated Chromecast is also expected to be launched at the same event.
