The problem with companies that used to support SOPA but have turned around, is that they supported it in the first place.
The problem with stopping SOPA is that the people behind it are committed to bringing it back in another form, some day, some how.
The problem with SOPA is that many of the bad things in SOPA are things that the U.S. government has been doing lately either unofficially or through "cooperation" with companies.
The defeat of SOPA will not be the end of the general problem.
The real solution is that we pro-internet, pro-innovation, pro-freedom folks need to be proposing our own legislation or, better yet, a constitutional amendment, which establishes freedom of speech, freedom to encrypt, and freedom to link as inalienable rights of all citizens.