Yep, tis a good writer gone to meet his maker.
What Dreams May Come, as a book, is a really great work. The movie was Starship Troopers to the book, but much like Troopers, the book and the movie can be enjoyed as separate pieces with the same title.
But I feel his masterpiece was "Bid Time Return" which y'all will know better as "Somewhere in Time". And true, the book and the movie differ some here and there, but both are just wonderful.
And that he did Nightmare at 20,000 Feet is just cool. Shatner and Lithgow did some good work with those stories.
I did not know he adapted The Martian Chronicles. Awesome. They did a pretty decent job for being TV back then.
RIP sir, you done well.