A couple of thoughts occurred to me, prompted by this remark by the OP: "I would love to know the correlation between what people use and what they recommended (doing that is fair enough - I recommend what I know as well), since almost nobody likes the Pentax option - I really thought it would be a closer vote..."
Well, it's clear that most people voted for the Nikon D50 for two reasons: (1) they didn't have a Pentax and don't know anything about them and (2) No Canon DSLR was on the list.
It is the first reason which should make you sit up and take notice. Yes, many people do NOT shoot with Pentax. Why? What implications does this have for you? Nothing to do with the perceived quality or non-quality of either Pentax bodies or lenses, but simply that as this poll has demonstrated (as well as many discussions on this site), unless finances are a consideration, Pentax doesn't seem to be the choice which first pops into people's minds when they are ready to buy camera gear. Nikon and Canon rule the roost when it comes to reputation. My very first SLR camera waaaay back in the 1970's was a Minolta. Nice little camera, and I learned a lot with it. My heart, however, was already lusting for a Nikon, and sure enough, when I later had the money, I went out and bought my first Nikon 35mm film SLR.
Anyway, I think you will find that most serious photographers own and use either Nikon gear or Canon gear (either 35mm rangefinders and SLRs or digital SLRs). Many not-so-serious photographers own either Nikon or Canon DSLRs. Both manufacturers have long-established reputations (Nikon's slightly longer, I believe). So more people have Nikons or Canons than Pentaxes. What does this mean for you?
Since we're addressing the possibility of a Nikon purchase, let's get on with specifics here. An advantage of getting the Nikon D50 is that you are much more likely to find that some of your friends are also shooting with Nikon lenses.... It's fun to go out shooting with others and to be able to swap lenses, see how a different lens can work for you. I've known people to lend others a lens when one is needed for a special occasion. Another advantage is that major photo stores such as Penn have rental services, too, so that you could walk into Penn and come out with 70-200mm VR that you've rented for the weekend. (I know the downtown store and the Tyson's store have rentals available, but I'm not so sure that the others do now that I am thinking about it. Chip can clarify this for us.)
For instance, you could come over to Virginia and go shooting with Chip and me and see how various lenses work on the D50: go from one extreme to the other and what fun you could have with the 10.5mm fisheye and the 200mm f/2 (Bertha) and the 80-400mm and the 300mm f/4..... You could also discover the wonders of IR conversion (Chip has had this done to his D50) and see how different lenses work with that.... This would give you an idea of the flexibiity of the Nikon system lenses. (Only problem is that it undoubtedly would give you a rip-roaring case of "Lens Lust!")
Seriously, though, if you do want to go out shooting before you make your decision and purchase, I would be happy to get together with you and let you try out the 18-200mm VR, the kit lens 18-70mm, and the 50mm f/1.4 (don't have the f/1.8) on either the D200 or the D70s (don't have a D50) so that you can get an idea of how this all works and feels and looks....
Getting back on-topic here, the other thought which was prompted by that comment also obviously occurred to others, and that is the advantages of a DSLR over a fixed-lens "pro-sumer" camera. That's why the Panny didn't rank too high in the poll. This has been addressed above so I'll just say that, yes, there are numerous advantages of a DSLR over a pro-sumer such as the Panny, the CP 8800 or the Sony R-1. One is the obvious (being able to change lenses to achieve specific photographic effects), another is that usually the pro-sumer cameras are a bit slower with the shutter lag and shot-to-shot. They often are not good performers in low light. As for viewfinders: there is nothing like a good optical viewfinder!! I hated the EVF on the CP 8800. So while these pro-sumers may have seemingly awesome zoom range they do have their liabilities, too and in the end are still not as satisfactory as a DSLR.
So there's where I'm coming from: a Nikon user from way back, having come to the DSLR from using SLRs back in the day, then a series of Coolpixes.....it was my less-than-satisfying experience with the CP 8800 which finally jolted me into buying my first DSLR. One thing I must add, though, is that while I was not particularly happy with the CP 8800, it was more to do with its incompatibility with my shooting style than it was anything to do with quality. We've seen some stunning images right here on this site by Seenew, who managed to work magic with his CP 8800..... That camera is definitely capable of super macros and excellent images (it has a fantastic lens) but it just wasn't the camera for me. And that's important to realize, too, that sometimes a particular camera or lens just isn't the right one for the photographer....