This is something that covers both classic and modern versions. Altough, it happened more often in the classic era and had worst consequences because of multi episodes for one story format.
But i'm always shocked to see them still doing it today.
Here it is:
the episode starts, something not normal is happening somewhere, there's a vilain in the shadows and later it is revealed that it's the Daleks (or Cybermen or Sontarans).
Is it just me that feels a complet waste of time to try to make it a suspense when in the first minute, everyone saw the title, like Victory of the Daleks or The Sontaran stratagem?
Why so often put the name of the vilain in the title?

In something like the Sontaran Stratagem, the sontarans had only just been redesigned, and while they'd been officially revealed, they'd never been seen in motion, so veiling them makes them a little fascinating - you see details before you get to witness the new sontarans in action.

Victory of the Daleks is a different case, since we did know full well it was a dalek story from the Beast Below's cliffhanger, and we basically knew the current dalek design. However, the Doctor didn't know they were involved, and for his reaction to be satisfying, he can't just pass one in a corridor - he needs a dramatic event to react to, so the conceal-and-reveal's more for the Doctor than for us. They do get it out of the way quite quickly.

Ok perhaps not the best exemples, even if those two did bother me, but there's loads of them:
-The Dalek Invasion of Earth
-The Dalek Masterplan
-The Tomb of the Cybermen
-The Silurians
-Planet of the Daleks
-Destiny of the Daleks
and on it goes. Agreed, the vilain is not always revealed further in the episode. But it has always bothered me to know who the bad guys are in the title.
Was just wondering if others thought the same thing

I was disappointed by the title 'Amy's Choice' as it meant it would feature Amy, err and she would have to make a choice, they gave away the whole story. Damn those writers

Seriously though, there is a good balance between titles that reveal and don't, i think all writers past and present have done a good job, it can't be easy being so inventive after all this time

Your first two are incorrect. At the time each episode had an individual title and the first episode was "World's End" for the former and "The Nightmare Begins" for the latter, so no giveaway about Dalek involvement at all.