With Justice Kennedy’s opinion today in KSR, it is now likely and unsurprising, but by no means certain, that the Chief Justice is writing the lead opinion(s) in the Seattle and Louisville equal protection cases. If, by some small chance, Justice Alito is voting with the more liberal wing of the Court, then there’s a chance that Justice Stevens would have assigned the opinion(s) to him. Justice Souter also has not yet written from the November/December sitting; but I think it’s unlikely that he was assigned the opinion(s) in the school cases.
There is also a chance that the two school cases could come out different ways — in particular, that the Louisville plan could be upheld while the Seattle plan is invalidated. If so, there’s still a chance that another Justice — probably Justice Kennedy — would write one of the two opinions.