I feel a little nostalgia reading about the K-01 as I've just sold $8,000 worth of Pentax equipment, having moved to NEX. If Pentax had come out with this earlier, I would probably never have moved.
However, I still have the KX, FA77, DA40, Tamron 90 and Sigma 8-16 in K-mount. Now, it looks like I'll sell the KX once the K-01 is officially announced and plough my now bulging bank account into the K-01 to use it with my remaining lenses.
The trigger point for me selling off my Pentax equipment came about 2 months ago, when I acquired a M-Mount Zeiss 35mm F2 lens and adapted it to my NEX 5N. At that point I was content to mostly use the 5N with my adapted Pentax lenses and the K5 for more (but rare) demanding situations. The Zeiss blew me away. Portraits just popped off the screen with super sharp resolution and the backgroup dropped dramatically into blur creating more 3D effect that I have ever seen... and the Zeiss was cheaper (bought in the U.S.) than my FA31. Both my FA31 and DA40 are really sharp lenses, but don't give me that look that I now like. The FA77 has some of that look and I'm glad I still have it. So I sold off most of my Pentax equipment to fund more Zeiss and perhaps Leica lenses. The NEX 5N and Zeiss 35mm also look and feel very elegant and are very balanced, rivalling the snazziest looking Olympus M4/3 setups (don't even talk about Panasonic).
There is now a 90%+ probability I will buy the K-01. My only dream now is that it would look like the Pentax ME/MX film SLR series in chrome and black. I would happily pay up to S$2,000 for such a body.