...is that he apparently wrote two of them during that time.

Aside from the LONG awaited "Peace Talks" which, as has been announced previously, is due to be released July 14 of this year, a second novel, "Battle Ground" is going to be released on September 29. It is being marketed as Book 17 of The Dresden Files. The last full novel to be released, "Skin Game" was Book 15, with the various novellas & short stories and the two collections of the same, "Side Jobs" & "Brief Cases" not counting in that enumeration. Reckoning just the full-length novels, "Peace Talks" would be number 16, even though "Brief Cases" came out between SG and PT. So as far as I can tell, "Battle Grounds" actually is a second full length novel, coming out only two and a half months later.

I think the implication is that it's more or less a two-parter, with the eponymous Battle of the second book being the result of the Talks falling apart.

Of course, the good news is only assuming civilization is still standing by then, and the books won't all be immediately stolen from the stores by crazed toilet paper scavengers desperate for any wipe-worthy sheets they can get their hands on.