It's not that big of a deal for holden to set the motor up for a single turbo (at least) or twin turbos, the saab version already uses a turbo!. Its got more to do with the demand and holden doesn't seem to think there is a market for it, they seem to think that V8's are more important which is kind of backwards, when it comes to fuel prices etc (they are great but there is more to motoring than V8's!). They won't bother if they are not going to take well to the public, a lot of enthusiasts will be keen as chips but that may not be enough to sustain the product.