See: http://digicame-info.com/2011/05/78-1.html
(in Japanese, Excite English Translation Here)
It is told that a new Pentax mirrorless with new mount will be announced by July/August. 3 colours will be available for this new model (which this information seems to be quite specific). And more importantly, another Pentax mirrorless will be announced later in the second half year of 2011. Besides, it also mentions about that the Nikon mirrorless will be announced in July.
The most interesting that we should note about is that the above blog author reminds us that the "informer" have been correct for the last several early supplies of the Pentax K-r, E-PL1 and E-PL2 leaked information, which I think I witnessed that for the last case of the K-r, which was found to be true. Actually, his informer mentioned about the K-5, too, which I think was the first time I heard about that name in a more confirmed tone, but not just pure imaginations.
At the same time, I see Photo Rumors today also tell about the new US pricing of the "upcoming" Pentax NC-1 mirrorless, from their own source:-
http://photorumors.com/2011/05/26/pentax-nc-1-mirrorless-camera-kit-will-be-priced-around-600/
So, I think this time the Pentax mirrorless should be true and it will come soon, so as the Nikon mirrorless. What a "rumour"! :-D
After all, whenever anyone surfs the Internet, one should have a strong mind of susceptibility and possess strong judgement so as to make the right filtering and finally more accurate predictions could be achieved. Always trust sources that are more sensible, insightful and had good past track records. This time, I think I will be bingo again, too! ;->