Before we begin, go ahead and watch the trailer (once again) so you can get a better idea what I'm talking about.
Doomsday has a very high chance of being in [Batman v Superman: Dawn of Justice](tag:711870). He is most likely the result of Luthor experimenting on Zod's body. Let us get down to the topic at hand.
We do not yet know if Doomsday will just be a reanimated Zod or if Zod's genes are what is used to bring life to some other creature. But he is there for the finale battle against Superman, Batman and Wonder Woman.
Lets look over some images and discuss how they factor in Doomsday.
Above we see Batman engaging his Grapple Gun to escape some heat vision. The trailer cuts it together to make it seem that it was Superman delivering the near fatal attack against the Caped Crusader.
But what if this isn't Superman at all? What if this is Doomsday, with resembling powers and abilities of that of Superman. Why would Superman be trying to KILL Batman? Their brawl most likely occurs before the battle with Doomsday and with Bats donning the special armor to take on Superman. They resolve issues after the fight.
Also it doesn't explain all the massive destruction that we see here.
The Bat-Wing flying overhead would have to be nuking the place to be the cause of all the destruction. Unless it's a enraged Kryptonian monster out for the kill.
Also Superman is shown covering hundreds of feet of destructed environment. This would not be the result of a battle between him and the Dark Knight.
This would also explain why Batman is rising in a patch of destroyed cables and concrete. Perhaps he just took a hit from Doomsday...We do see what is presumably his Bat-Mobile trashed behind Wonder Woman.
Speaking of Wonder Woman, the Amazonian Warrior is seen partaking in some rather epic battling herself.
Clashing her bracelets together seemingly creates a giant massive shock wave.
This may be her deflecting some heat vision as well, but when you watch the trailer in slow motion, you'll see that she is actually clashing those bracelets together.
Wonder Woman also takes a mighty hit from...oh I don't know...maybe...Doomsday!
To conclude, this image below could be the aftermath of either Batman infiltrating Lexcorp or Doomsday escaping or being released by Luthor.
It does look like the one who killed Superman will make an appearance. We'll all just have to wait and see come March, 2016.