Here are a few thoughts from my recent experience. I was in a similar position a few weeks ago. I have used various PnS cameras (and a very old Oly film SLR) for many years, including an Oly 5060 underwater. However, I really wanted the extra speed, flexibility and low light performance of a DSLR (particularly for a trip to WDW). I may also house the camera for underwater use at some point.
My initial decision point was what lens system I wanted to go with, and which camera I felt most comfortable with. I eliminated Pentax, Sony etc because of the greater range of lenses available for Nikon and Canon, plus the greater choice of housings available for these brands if I took it underwater. When moving to a DSLR I believe I am buying into a lens system more than a specific camera body.
I tried a D40, D60, and D80, plus a Canon XSi in various photo shops, and preferred the controls and handling of the Nikons. I eliminated the D60 as it offered few additional features to the D40 (eg still had no focus motor in the body), but cost £100+ more than the D40 here in the UK. At this time the D90 was being launched, but at £800+ with a kit lens, was more than I was prepared to pay for a first DSLR. I discounted the D80, as, even though the prices were coming down, it still was not a cheap camera.
Finally I looked at the D40.
Amazon had it for £220 with the 18-55 kit lens. For that price I could buy the kit, and still have enough to buy another decent lens (compared with the XSi or D80) . Also, as I had no legacy lenses, the absence of a focus motor on the camera was not an major issue. I intended that any future lenses I bought would have a focus motor and vibration reduction anyway. The megapixel count was a non-issue to me as the D40 has a good sensor, and I have previously enlarged 5mp shots from my Oly 5060 to a good size with no visible loss of quality.
So I now have the D40, and, for the price, I am very impressed. It is well built, the auto-focus and stabilisation works well, and, as far as I am concerned, it works very well in relatively low light, even with the kit lens. For the price of reasonable PnS, I have a camera that offers far better image quality (especially in low light) than any PnS or Bridge camera. In a year or two I may outgrow the camera body, but I will (hopefully) have learned how to use a DSLR effectively, and can re-use the lenses on any other digital Nikon body.
Unfortunately, many do. I have even seen a significant number of posts on various boards where people have been sold that very lens and a D40/D40x/D60 and are on the board asking what is wrong with their lens b/c it will not focus. They are not very happy when told that it will not AF. Then on places like DPReview, they are publicly ridiculed and run screaming.
