The five-disc set will include the last twenty episodes of the first season. Volume 1 included the first 19 episodes.
That is all the information about the new DVD set available at this time. For information on the Perry Mason Season 1, Volume 1 DVD, click here.
For more on Perry Mason and author Gardner, see my Weekly Standard article on "The Case of the Bestselling Author" here. For more information on the Season 1 Volume 1 DVD and an important addition to my Weekly Standard article, see this Karnick on Culture post.
Here's the cover art for the DVD edition: