However, these are not officially posted at the K-5 sample page, which is yet saying "Coming Soon" at this moment:-
http://www.pentax.jp/japan/imaging/digital/slr/k-5/ex.html
(in Japanese, Update: The above page has been officially published now..)
Anyway, Enjoy! :-)
P.S. For the lens used and exposure settings per picture, use the latest version of the Pentax Digital Camera Utility to inspect.
Read Also:-
Official Full Size Samples of K-r is Out
Some More K-r Full Size Samples (from Users)