Do not give up hope. Jim Cameron still wants to make a movie of Ringworld and who knows where that could go.
But Gil Hamilton and ARM need a lot of adapting before they can be presented. Same with Protector (see my screen name for my bona fides). I actually personallly provided Niven with an out (short version - "Protectors lie") for his totally bogus evolution/biology from that book (which is one of my favorites anyway).
Can you imagine the long form series on SciFi of "Known Space?" Now, heres a challenge: who to cast for Beowulf Schaeffer? How about Louis Wu? The voice of Nessus? Teela Brown? Truesdale? And who would you have do the FX?
And then to contemplate the Niven/Pournelle collaborations on Footfall, Lucifer's Hammer and Fallen Angels. The mind boggles. I would kill to get the part of Harry Red!
Louis Wu? Wallace Shawn.
Teela? Either Gabrielle Anwar, Angela Lindvall, or Natalia Vodianova (both were in CQ).
Beowulf? Jude Law.
A Puppeteer's voice, I think, woud be three or four human voices run through a processor. They did not have very human-sounding voices, unless a human spoke as a pipe organ mixed with a bagpipe.