This from Wikipedia regarding previous updated versions:
Cosmos had long been unavailable after its initial release because of copyright issues with the included music, but was released in 2000 on
worldwide NTSC DVD, which includes subtitles in seven languages,remastered
5.1 sound, as well as an alternate music and sound effects track. In 2005,
The Science Channel rebroadcast the series for its 25th anniversary with updated
computer graphics, film footage,
digital sound and updated scientific knowledge that had occurred in the past 25 years. Despite being shown again on the Science Channel, the total amount of time for the original 13 episodes (780 minutes) was reduced 25% to 585 minutes (45 minutes per episode) in order to make room for commercials.
In 2009, Freemantle Media Enterprises released in the UK, a 5-disc DVD set of the original series plus with bonus science updates. The DVD set was digitally restored and remastered. Although a little grainy in places, it is without question, the best reproduction of the original series to date."
I recently enjoyed Brian Greene's 4 part Nova series based on his book called "The Fabric of the Cosmos".
http://www.pbs.org/wgbh/nova/physics/fabric-of-cosmos.html
Much like Sagan, he is able to convey complex ideas in a way that even someone like me (a math moron) can understand conceptually and I think he makes a very good "heir apparent" to what Sagan did for bringing science to the masses.