Only the anti-indecency and anti-obscenity provisions were struck down. Section 230 remained, and is to this date one of the best pieces of legislation regarding the internet; it largely immunizes an online service provider against the activities of its users.
How does that relate to the DMCA's Safe Harbor provisions? I don't know as much about the CDA. Mostly I'm curious as you say this is "one of the best pieces of legislation", and how it relates in strength to DMCA's own provisions.
CDA 230 explicitly excludes safe harbor for intellectual property claims. DMCA 512 provisions created a safe harbor for that gap in CDA 230 (provided you meet certain criteria).
http://en.wikipedia.org/wiki/Section_230_of_the_Communicatio...