Aer Lingus have being refused promission to land a KTW a number of times. Ryanair will get top priority from KTW as will LOT. I was on a Ryanair flight and around 12 flights diverted to KTW and there was no bus transfer to KRK as they hadn't enough to take 12 loads of passengers. Warsaw is used a lot for KRK diversions but again they have also being refused promission to land. In most cases if KRK has problems with weather other airports in Poland do to. Its up to KRK airport to actualy spend money on instaling equipment to stop this. Berlin is used as in most cases there is no other option.
As I say its not confirmed if it will be dropped as it was included in the summer 13 schedule a few weeks ago but not put on sale.