  We use the most recent Type-Ia Supernova data in order to study the dark
energy - dark matter unification approach in the context of the Generalized
Chaplygin Gas (GCG) model. Rather surprisingly, we find that data allow models
with $\alpha > 1$. We have studied how the GCG adjusts flat and non-flat
models, and our results show that GCG is consistent with flat case upto 68%
confidence level. Actually this holds even if one relaxes the flat prior
assumption. We have also analysed what one should expect from a future
experiment such as SNAP. We find that there is a degeneracy between the GCG
model and a XCDM model with a phantom-like dark energy component.
