I would imagine that there's still a little bit of room for growth this winter at MAN as I don't believe that 2 return sectors per day is utilising an A320 to its optimum. Unless they're adding more Geneva services? I would believe a 4th unit will be in use next year (probably from Winter 2010) with the 5th unit not until 2011 at the earliest.
The blurb that accompanied these new routes does indicate that there may be more of a focus to city break destinations away from the bucket and spade routes that has been the norm.