Alien: Covenant trailer

The night of Christmas Eve (twelve o'clock, technically Christmas day) the trailer for Alien: Covenant debuted.  Here it is: https://www.youtube.com/watch?v=H0VW6sg50Pk#action=share .  As far as I can tell, everything looks great.  I particularly like the back burster and the shower scene.  I'm a little unclear about some of the things that are going on (how many Davids are there, three?. . .  is that Elizabeth Shaw in the hoodie?. . .  how many types of Aliens are there? etc.) and I'm hoping this will be clarified once I see the actual film.  But so far, everything looks terrific and I can't wait to see it.  I hope everyone, in the meantime, has a Merry Christmas and a Happy New Year!