Well actually I feel it's a genuine concern. As you probably know, one of the reasons why anyone would stay with the Pentax line is the K mount compatibility. As I understand, it is the only mount among the reasonably priced systems that is both downward and upward compatible. The Nikon F mount is only downward compatible, to the best of my knowledge.
If Pentax really were to release a DSLR that is not downward compatible, its users are in for a nasty surprise.
