My take is this: Th\' Stamper brothers want to sell Rare and retire, and Nintendo doesn\'t think they need them.
MS gets Rare, Nintendo makes money, the Stampers make money. SFA is the last GCN game Rare makes.
Nintendo no longer has to carry what they consider to be a burnt-out studio. Using the millions of dollars they obtain from Rare/MS, they may invest in another developer. Sega is rumored, but I don\'t think this would be so good. For one thing, Sega is worth far.. far more than Rare.. defeating the purpose of selling Rare for Sega..
And, Sega\'d have to port all of their upcoming releases to GCN.. and this would take a while.