In the episode, it was showed that Capaldi was the thirteenth Doctor. And, before he was shown, the Timelords in the room counted 12 Doctors, including the Time War Doctor. So, Capaldi is the last Doctor, since he can regenerate only 13 times (according to some source I can't remember, tho.)
And Capaldi has signed up only for one season, so we shall se, if we get only one season of the Doctor or what.
BUT - to the episode!
I loved it! There were a couple of obvious plot holes (like, how they didn't wrap up the cliff hanger from the last episode and what happened to the zygons), but I loved it anyway!
I personally love the plot twist that they're going to save Gallifrey anyway. Some might not like it, some might. And I am one of those who approve this. I've always found Gallifrey a fascinating civilization and always wanted it to flourish, and finally, it can! The ending was a little "Whaaat the hell happened", and I'm wondering if the War Doctor still thinks he destroyed Gallifrey after that...
And they FINALLY wrapped up what happened with the Queen (in one episode, the Doctor was told that the Queen was very displeased with him and he didn't know why. And was it in the "End of Time" where he returned and told that the title "virgin queen" isn't that accurate anymore...?)
And I'm SO waiting for these certain plot holes to resolve. Was the Doctor able to go to the Time War only thanks to the Moment? Or why could he go through the "timebubble"? And what happens to the End of Time -episodes after this?
But the communication between the Doctors, priceless! Oh, and the bunny! And and and so many great things I just can't think of! ;__;
I JUST LOVED IT.