The A-Star is by definition an 'A' segment car, i.e it is in the range of Alto or at the most Wagon R. Don't expect anything bigger than 1.2 liter petrol engine on that car, and knowing Maruti they wont offer a diesel option.
The specs given at the auto-show said that it would have a 1 liter all-aluminum petrol engine that meets EuroV specs. If so that would be terrific.
It would be totally pathetic if they released with the Wagon R/Alto engine and gearbox.
Having said that, if they do, there will still be losers queuing up to buy it.