I presume that the swiss aircraft that will be operating the Cardiff to Zuerich route will either be a ARJ-100 or BAe 146-300. These aircraft, which operate with a mix of business & economy class seats usually seat between 90 & 100 passengers.
bmibaby are basing two Boeing 737-300 aircraft, and I believe they are operating a full schedule from here. There are no plans to expand from CWL in the forseeable future we are told, but the airline will continue to expand their co-operation with Air Wales, with 6G operating shorter & more frequent flights, whilst baby operates "leisure" routes like AGP & FAO.