I wouldn't describe the K5 as looking old or retro itself, but the "limited" lenses have a kinda retro feel with their size and build quality. I brought in my K5 to work yesterday to show my co-worker. He had never held a Pentax DSLR and was amazed at the solid build of the K5 and weatherproofing....then he heard the quiet shutter and saw a quick high ISO shot and was really impressed.....then I broke out my limited collection and he was uber impressed.
I was hoping the K-01 would have had a more retro design like the new Olympus or very popular/gorgeous X100 vs. the modern look they went with. I can just image a X100-ish design with any of the gorgeous limited lenses.
Fact is, even while performance will always win over, as much as we carry our cameras they do become a fashion accessory of sorts. People...such as that girl...will comment of the aesthetic value of the camera vs. the performance especially if it is a design they have not seen before.