Any of these make it into the DawnGuard DLC?
I don't remember anything about crying child, but the rest is in the DLC.
Ok i'll start, how big are the new landmasses, can we customzie the two stongholds and did you enjoy it?

Soul Cairn isn't HUGE, and there isn't too much to do as the trailers suggested, but the big secret here is the Forgotten Vale, an immense "landmass" of sorts that you find deeper into the quest line.
As far as customizing the fort/castle...they are upgraded/furnished somewhat as you progress into the quest lines, but the end results are still filled with boxes/cobwebs/not quite what you'd expect. If you're expecting a payed clean up similar to the Dark Brotherhood, there is none.
Is soul cairn the only new landmass?
werebears?
Achievements?
There's the Forgotten Vale, which is found deeper into the quest-line. It's HUGE, Soul Cairn is tiny in comparison.
NO WEREBEARS.
FROST GIANTS, Actually no...Can you write a detailed review that says its pros and cons with no spoilers?
I'm not very good with reviews, otherwise I'd write one up. You'll find Frost Giants in the Forgotten Vale, a huge landmass of sorts found later into the main questline.