One related to music, is the record, or more specifically the gramaphone record. It was cassettes which supposedly started destroying the record, and then the CD was the nail in the coffin... or so people said. Now, digital music is supposedly the end of the CD, and yet records are making a strong comeback. Granted, in limited and small productions, but still are thriving with some 4 million sold in 2011:

http://technorati.com/business/article/ … cords-are/

I wonder if in 20 years CDs will "make a comback"

Tough call.  I never use vinyl but I won't deny that analog has some benefits over digital, although if you bump up the digital quality enough I doubt most people could tell the difference.

Records sound better, simple as that. Digital sound is missing data found in analogue sound and the end product suffers. And also records can't be blown up to unlistenable levels like most CD's nowadays are.