Well, here's what Alfa told me:

"All we can say is that we will see the GTA badge sooner but on another car rather than the Alfa 159!"

A 159 with a big engine doesn't sound very GTAish to me.... Also, Fiat is confusing their brand values if they put Ferrari engines in Alfas. I think the 149 GTA is far more likely, as they have so much riding on that car.

Cheers,

Nigel