Two questions.
What adventures (low level) have been released to Realms 4th ed. (bought or Insider)?
I loved the huge Undermountain boxed set - how do I use this for 4th ed.?
Thx for any responses.
-Khelben
Please see this link for the Bibliography of the Forgotten Realms in 4E by our very own Christopher Rowe.
It has links to several 4E adventures for the Realms.
As to your second question: I too loved the Undermountain boxed set(s). I've many pleasant memories of them from the days when we used to play 2nd Edition D&D.
How to use it for 4E though.....easy, I should think. Follow the advice on page 3 of the Ruins of Undermountain Campaign Guide and simply substitute the 4E Rules where appropriate.
I wouldn't fret over the recent history: i.e. the Spellplague, Halaster's seeming demise, the addition of The Warrens beneath Dock Ward and Castle Ward, and so on. That stuff's all background flavor anyway.
Were I you, I'd find a way to keep Durnan around (or something masquerading as Durnan). Maybe add a section to his in at the Yawning Portal called "Mirt's Room" in honor of his long lost friend. But that's just me.
Best of luck to you Khelben7 and don't hesitate to throw more questions our way about this or any other subject.