Majorities don't matter when the filibuster is threatened.
I don't think the GOP Senate has the guts to pull the nuclear option over a SC nominee. Not with Frist and his stock sale problems in charge.
Sadly, you may be correct regarding the nuclear option. I just think a SCOTUS fillibuster would not fly with the public without some serious justification. The dems have not forgotten what obstructionism reaped them in Nov. 2004.