From a recent signing event, he now has a place to work on this and now that "Brief Cases" is out and his promotion for that is done (or mostly done), "Peace Talks" is on the way. I believe he said to release late fall. So, comparatively - soooooooooooooooooooooooooon.
Peace Talks is really part one of a two part novel.
The second part was released a few months later.
Both it and Battle Ground (Part 2) made is momentarily to the NYT Bestseller list, so I am sure that any long term Harry Dresden lovers have read them by now. Others? Go thou and do likewise. Battle Ground is the most accurately titled novel that I am aware of. It starts with a fight with a legendary monster and then gets serious about the continuing mayhem.
Overall, it could be faulted for being so heavily into conflict to the exclusion of character development, always a strength in the series.
But as a long termer it did not bother me a lot. I would suggest picking up another of the series, (perhaps Skin Game or something earlier?) if you are brand new to the series.
One piece of the resolution at the end did strike me as unsupported, but I would guess that Butcher had it happen as part of his long term outline of progress of the character.
Rating? 4 of 5. for well handled mayhem, along with the standard humor and now well developed characters. I would put it at about average for the series, half better, half poorer.
But I like them all so that is not a downcheck for any of the Dresden Files.