Hey! thanks all!
Two beers later and we desided to go with leavingwt's letter - It feels pretty good to be able to write *something* to them so it does not feel like we are being cowards, and we really liked that it kept the 'depressive' option open. Its their move next, so far they have been pretty nice and no turned up unexpectedly, so hopefully this will buy us time.
As a side note - my girlfriend is reading leavingwt's letter :-). So i guess something good did come out of this ;-).
-mr/ms Bohm, of the scared sheep-class.