I don't think so, unless you know of some relatively unknown posthumous
books that have been released since Sagan's death on December 20, 1996?

Billions and Billions came out in 1997, a collection of articles he wrote
mainly for Parade magazine. Comet was an updating of his 1985 book to
coincide with Hale-Bopp’s appearance in the sky in 1997.

And late last year a collection of his interviews going back to 1973
was released in book form.

http://www.upress.state.ms.us/catalog/fall2005/conv_carl_sagan.html

But I don't think Sagan has been quite as "prolific" as Fenyman.

I actually don't blame Ann Druyan for releasing these lectures, as most
of the public seems to be far more interested in Sagan's religious views
than his scientific ones. At least the more vocal ones. It's a lot like
what happens with Stephen Hawking; people are always asking him about
God instead of his true knowledge base, cosmology and astrophysics.

Sagan and Hawking certainly were and are smart men with deeper insights
into the subject than most, but the public keeps thinking they have some
special insight or communications path to the Big Guy in the Sky.

There are a lot of other lectures that Sagan gave in his lifetime which I
would also like to see in transcript/audio/video form wherever possible.

It would also be quite wonderful to have his hundreds of technical and
scientific papers in one or several collections. I can only find a few on
the Internet.