Lyle Denniston has some encouraging reports from inside the SCOTUS, where the McCain-Feingold law is facing its stiffest-ever challenge. The new court seems more skeptical of the law than the pre-2005 court.
The main thrust of the Roberts-Scalia assault during the arguments on FEC v. Wisconsin Right to Life (06-969) and Sen. John McCain, et al., v. Wisconsin Right to Life (06-970) was that the "electioneering communications" restrictions adopted by Congress in 2002 do not appear to leave enough room for an advocacy group to put up broadcast ads during election season that seek to raise questions about the policy stance of candidates without directly urging voters to vote for or against such candidates. Just last Term, the Court had ruled, in a post-McConnell decision in this same Wisconsin Right to Life dispute, that "as-applied" challenges could still be made to the "blackout" clauses in the Bipartisan Campaign Reform Act of 2002.
WRTL's lawyer, James Bopp, Jr., of Terre Haute, Ind., appeared to make real headway with his complaint that "as-applied" challenges would seldom succeed under the "blackout" provisions, justifying at a minimum a narrowing interpretation or, perhaps, an overruling of that part of McConnell. Roberts and Scalia helped him significantly, but he also held his own against sometimes sharply tinged questioning from Breyer and Souter.
I didn't go to see the arguments, but a friend who did says the non-Scalia justices were "holding their cards really close." It's really a matter of what Alito decides.