To be specific, like all U.S. Courts of Appeal, the Federal Circuit hears cases in panels of three judges, drawn from the overall pool. In certain circumstances (notably, anything that requires a prior panel opinion to be overruled), a majority of the judges on the court may vote to rehear a matter en banc, in which case all the judges on the court vote on the outcome.

If I recall correctly, the panels are assigned randomly as the cases come in, so if there is a marked division in opinions within the court, the outcome can depend heavily on the luck of the draw.

Justice Stevens wrangled four votes on the Supreme Court for that proposition as recently as 2010. If we could replace some of the pro-software patent majority (Roberts, Scalia, Kennedy, Thomas, Alito) in the Bilsky decision, maybe Breyer could wrangle five votes someday.

Of course, the CAFC might just overrule the Supreme Court if that ever happens.

(You say the CAFC can't overrule the Supreme Court? Wrong-o! [0] Don't read the link unless you're in a profanity-safe environment; not because it contains profanity, but because you're likely to shout some.)

[0] http://www.ipwatchdog.com/2012/03/20/supreme-court-mayo-v-pr...