I don't think GM knows the answer to this question. I think they'll wait to see how the Northstar XLR does, and then conduct some research on whether anybody beyond the Hip-Hop/Hoops world would go for the V12.
Ironically, I think the availability of a V12 is essential to selling the V8. Without the halo car, the XLR is a more-expensive Lexus SC, not a less-expensive Mercedes SL.
Another factor is whether GM will make more money dropping V12s into XLRs or into Escalades. I don't think anyone will debate that GM's first inclination is to build whatever makes the highest short-term profit. No doubt in today's market they'll sell every Escalade V12 they can assemble. Though it seems criminal to put such a sophisticated engine in a live axle truck.
.Jinx
Ironically, I think the availability of a V12 is essential to selling the V8. Without the halo car, the XLR is a more-expensive Lexus SC, not a less-expensive Mercedes SL.
Another factor is whether GM will make more money dropping V12s into XLRs or into Escalades. I don't think anyone will debate that GM's first inclination is to build whatever makes the highest short-term profit. No doubt in today's market they'll sell every Escalade V12 they can assemble. Though it seems criminal to put such a sophisticated engine in a live axle truck.
.Jinx