I think so but not solely by Butcher. Either he'll take on a co-writer who will take over the majority of the writing with Butcher focused on plotting the story, editing and punching up the drafts, or the publisher will take it over at some point. I think it more likely to be the former and frankly, I'm a bit surprised that it hasn't happened already.
BTW, I won't be surprised if Butcher's son becomes that co-writer or successor-to-finish.
A more personal question: At what point do you stop caring enough to purchase the books (whether in hardcover or waiting to buying the paperback) and either borrow from your public library or just quit reading them at all? FWIW, I think I'll always be interested in the resolution of series even if that means just reading the summaries on Wikipedia or some other website.
The most personal question: Do you think the series be finished during your life expectancy? I have a friend in her late 70s who has quit reading the series because she knows she won't be around for the finish but even more immediate, the gap between books became long enough that she had to do homework to remind herself about where things had been left, the peripheral characters, etc. and that wasn't worth it.