A few years ago I asked for a novel featuring Mirt as the main character, but I never got around to saying thank you to WotC for giving me the next best thing: keeping Mirt alive and active in the current era of the Realms.
Thus: Thank you, WotC, for keeping Mirt the Moneylender around in the Realms.
I look forward to reading more about him in future Realms novels, and I hope one day you will consider returning him to Waterdeep, that he might explore it anew, discover what has changed, confront his pain over the loss of family and friends, and give us a window into Waterdeep as it exists in the post-Sundering Forgotten Realms.
p.s.: I hope you guys are having a blast and as much fun as possible working on D&D and the Realms. I am convinced that the best gaming products I own were made when people were having a good time while doing the work.
It looks like Mirt is about to discover some deep, dark secrets of the Realms: http://realmssecretariat.com/unhistory-2/
WotC: how about a new Realms colum on the website?
Instead of a continuation of the "Forging the Realms" articles, how about "A Mirt's Eye View"?
Elminster could still interject his opinions and wisdom from time to time; the dangers Mirt barely avoided in his last daring escape, for example, and the grim fate that would have awaited him had he been captured.
If instead you'd like to put this behind a paywall, as a replacement for the "Eye on the Realms" series that was published in Dragon and Dungeon, then please do so, because I will happily re-up my subscription just to get my hands (well, eyes) on a new series of Realms articles featuring Mirt and his explorations of the post-Sundering Realms. 
Now that is some good news you can chew on, Miscallany!
i have always been a fan of Mirt, that fat old piece of ****! Lol, jk...but in all seriousness, Mirt had made camero appearances in most of my games. In 3e, I had him as part of the Harpers, help the PCs break of of jail in Luskan. And, in 4e, I had him be the owner of a small trinkets (and magic shoppe) in Neverwinter. Heck, even now in my current 5e game, I plan on having my PCs meet him after completeing the Wave Echo Cave in LMoP. Basically in LMoP, Gundren Rockseeker, the dwarf who hired the PCs in the first place to help him with the mine, offers 10% share of the mines profit if they can reclaim it from the Black Spider and rescue any of his brothers, if possible (if alive!). I'm was planning on giving my PCs a small, but generous amount of money each level (possibly like 200-400 gp) for the next 5 levels to represent payment and profits coming from the mine. i even created the Bank of the Sword Coast, so that players can grab thier payment at any semi-populous town with loyalties to the Lords' Alliance (by now, i thought that the Lords' Alliance would for sure have some sort of banking monopoly in 5e). So they can pick thier payment up from Neverwinter, Waterdeep, Daggeford, Baldur's Gate or any of the cities they find themselves in our sandbox campaign after LMoP.
Alternatively, I'm having Mirt come to Phandalin to scope out the news he's heard about the Lost Mines and Gundren, and offering the PCs a buyout/payout settlement sort of thing, whereby he will pre-pay them ahead of time probably (75-80%) of thier shares. So my PCs can opt for steady stream of cash per level, or take Mirt's offer and get a nice sizeable payout now, before traveling to the next adventure (in Waterdeep).
of course, I'm not making Mirt any sort of swindler, or anything. In this case, he's simply jumping on good info and offering an honest buisness transaction. He is also only making this one small appearance in my game so that it has a Realms flavor without complicating things too much or making unneccessary quests and such,
i like Mirt.
from what I heard, he was trapped in a magical axe, and that's how he survived the Spelplague and withstood the timeline jump.