The screen of all WP7s is 480x800. 1080p is 1920x1080. So that's a no. I'm not sure just how much you'd be able to tell on such a small screen, though.
Yep I know and I personally don't bother if it can play it or not but one of my friends wanted to know.
Anyway,it may not officially support 1080p vids but may play them with 3rd party apps.
Because,iPhone 4 has a 800MHz CPU and can't directly play 1080p vids but with a software called "filer" it can play 1080p mp4/mpg movies so maybe something similar is possible on the Titan
I would guess that it can still play them, but they would be scaled down to WVGA. Kind of like how you can play bluray on a 720p television. It isn't 1080p, but it'll still show up at 720p, regardless.