Peter,
. .I think BMIBABY is a rebranded version of BMI.
Given that it will serve primarily leisure destinations (excluding Dublin) like an IT charter, I am sure passengers will not be too confused when given nuts and water vs. normal service.
As far as cost structure is concerned, I doubt it will be tweaked much. No doubt it should - either that or ensure higher aircraft utilization/frequencies somehow to reduce unit costs.
Should be interesting to watch as GO, the traditional charters and possibly Ryanair also stir-up the hornet's nest. I am sure the local ATC will be ramping up as well.
. .Cheers