Professor Miller writes the following:
I … did a little digging on opinions issued from the Court's first two sittings – the one starting Oct 5, and the one starting Nov 2. Bilski was in the second of these two sittings . . . If the past is any indication, one would expect each Justice to write about 3 majority opinions from this group. Perhaps Justice Sotomayor, as a newbie, would be assigned 2. . . .
The Court has issued opinions in 18 of the 26 cases from its first two sittings; thus  remain. Among those yet to issue, there are some that are likely to produce fireworks, such as (a) Stevens, the animal cruelty video/free speech case; (b) Buono, the religious symbol on gov't land; (c) McGhee, the prosecutorial immunity case; and (d) Graham and Sullivan, both challenging Florida's life-without-parole sentences for juveniles.
From those two sittings, the following Justices have written the stated number of majority opinions:
I don't know when Bilski will issue. But I'm pretty confident Justice Stevens will author the majority opinion. He is, of course, the author of Parker v. Flook and the principal dissenter in Diamond v. Diehr.