No. Viacom is still within their rights to have Youtube take down any material that constitutes copyright infringement. All this suit means is that Youtube can't be held liable if users post copyrighted material (as long as they take it down when they receive a notification of copyright infringement).
Not sure why people are getting so excited; unless I missed something, this isn't some big landmark case that is going to radically affect the way we do things or anything. Absolutely nothing is going to change other than that copyright holders can't sue the video-sharing sites themselves for copyright infringing material posted by users as long as the sites take down or block access to the copyrighted material when they receive a notification claiming infringement (assuming of course that the content actually is infringing on the holder's copyright).
So really, this means absolutely nothing for anyone other than the copyright holders and the website owners.
