I don't know if this is the proper way to report bugs to you people but I couldn't figure how to actually submit a proper bug report so I'll do it this way.
I downloaded TTW on Friday and started a playthrough, so far I've seen the following bugs:
The gate to Megaton (the thing Deputy Weld stands near and is supposed to open when you approach) doesn't actually open.
Polowski Preservation Shelters cannot be opened by activating them. The "Press E to activate" message comes up, but pressing E does nothing.
The Gate to Tenpenny Tower doesn't actually open when you talk to the Intercom. the security guard acknowledges you but the gate doesn't actually open.
In the Tenpenny Tower Lobby There's a bunch of red rhombi with exclamation points in them. I have no idea. Everything else seems to be fine though.
The Calvert Mansion in Point Lookout has some interesting happenings:
The gas tank in the west wing of Calvert Mansion doesn't actually spawn (breaking The Local Flavor) and Desmond just stands on the 2nd floor entrance near the sniper rifle while looking mean toward the west wing.
The gas tank in the east wing doesn't disappear when exploding, it explodes, bounces around and you can shoot it again.
Desmond won't talk to you even if you force start Walking With Spirits via console command. He just talks about having to repel the home invasion.
I Found some stock Combat Armor in DC, it had a weight of 12 but I can't find any corresponding item in the GECK (anything with the name "Combat Armor" and a weight of 12) which implies there's something reducing the weight of armors in-game.
Feedback (not bugs)
I think the DC weapon prices are too high in general; it makes acquiring huge amounts of money absurdly easy. I know some of these weapons (Hunting Rifle, Flamer, Combat Knife, et cetera) are like that from New Vegas itself, but the huge availability of valuable weapons makes money essentially a non-issue.
Union Station is Gorgeous.