About to Start Reading Stephen King's Mr. Mercedes

When I found out a several weeks ago that Stephen King, currently my favorite author, was coming out with a new book, titled Mr. Mercedes, I went to my local public library's website and placed a hold on the book.  Even though the book hadn't yet been published, I still initially found myself far down on the waiting list.  Well, the book's been out for a few weeks and, apparently, my county library system had ordered several copies of it because I was notified yesterday that it was ready for me to check out.  Today I got it and plan to read a good portion during the weekend.

I read somewhere recently that Stephen King plans to make Mr. Mercedes the first book of a trilogy...I'm not so sure that I like that idea very much.  No offense to the "King" intended, but his track record in this area in somewhat inconsistent.  He stretched out the first four volumes of his seven-part Dark Tower series over more than twenty years...and then finished it by rushing through the last three in a two-year span!  And his collaboration with Peter Straub of the connected novels The Talisman and Dark House was even more unsettling: their publications were seventeen years apart!  But more than that, the ending to Dark House clearly sets the stage for a sequel, which thirteen years later I am still looking for and see no sign of. 

Yes, I'm a little bit dubious of Stephen King's track record with series...at least pertaining to the regularity of their publication through time... but I also understand that he was engaged in writing a lot of other high quality books in the interim periods.  It was a lot different for someone like J.K. Rowling, who was focused on writing the Harry Potter series to the general exclusion of other books...