Before the upcoming Pentax DA 560/5.6 comes and if you really need one, here is already an alternative option, i.e., the Samyang/Walimex 650-1300/8-16 telescope:-
The "lens" can be mounted onto a K-mount body via an T to K adaptor. It is sold at 299 Euro or a bit more than 300 US$. Here are some reviews of it, don't expect stellar optical performance, though:-
And two sample pictures taken with it:-
So, adapting a telescope to a DSLR/ILDC may or may not be a good idea. That depends on what you want actually. It offers a cheap solution for a very long reach, nevertheless.
Total Lunar Eclipse (2011-12-10, at Hong Kong)
O-GPS1 Astrotracer Examples
Monday, February 13, 2012
Mounting a (Cheap) Telescope onto a Pentax (K-mount) Camera Body