So how many of the locations are definitely back? And how many are gone? How much, aside from the ash everywhere, has the island changed?

Posted in spoilers because I don't mind if one or two locations returning are "secret" - I'd still like to know.

Just out of interest as I have been playing Bloodmoon recently. Also, are the dwemer ruins explained?

No, of course not. There's one on the shore, in fact.

Anyway, secret? Miraak, like you've seen on the trailer, has people building new stuff around the Standing Stones.

Then there's Skaal, Fort Frostmoth (in ruins), Raven Rock has a bit of Imperial architecture, but mostly it's new Redoran crab homes.

The leak mentioned Altar of Thrond, where you cured lycanthropy, Brodir Grove, Kolbjorn Barrow and Castle Kaarstag.

I've just seen the LPs so far, dunno.

Anything left of that glacier in the north-west? I think Miraak Temple is there now... wonder if it's made up of the old mazes there...

Edit: No I've seen where his temple is now. So is there something at the old glacier?

Well, it's not cell-by-cell Bloodmoon. Those hexagonal rock formations are a new addition...I've seen where those happen in nature, but they still throw me off.