The ninth series of Doctor Who ended on 5th December 2015, and in that time the only Doctor Who the BBC felt we deserved was two stand-alone Christmas specials and a paltry spin-off. Now, at long bloody last, we know when the tenth series is due to begin. April 15th.
— Doctor Who Official (@bbcdoctorwho) February 25, 2017
As you can see, there's also a trailer that shows us very little. Also a tagline 'Time for Heroes', which could be the name of the first episode, or it could not. We also don't know what time it'll be on, but around 7pm sounds about right. There's isn't very much to go on, so I'm just speculating.
We should at least be thankful that the BBC has got this announcement out of the way now, rather than getting up to its old tricks and only giving people a few days notice.
Doctor Who series 10 will be the last series with Stephen Moffat as showrunner, and Peter Capaldi's last as the 12th Doctor. Also along for the ride are Matt Lucas as Nardole, and Pearl Mackie as the new companion Bill. The above trailer is also available to watch on YouTube, in case you wanted a version with a few more pixels.