The D700 is less megapixels but it's a full sized 35mm sensor camera. The APC sized sensor is 30% smaller. And then canon is stuffing 5 more megapixels into it. There's a line there somewhere (i'm not sure where it is) that if you cross it, you are not doing yourself any favors by adding more megapixels. The megapixel war is driven by uneducated consumers, not the camera companies.
David, you have to think of it like this. I know you are like me. You want to buy the best you can afford. But you need to ask yourself if you really need the best, or can you save yourself some cash. The reason I was suggesting the D300 instead of the D700 is because the 700 has features that you are not really going to benefit from. Faster frame rates, more customization, full frame sensor (how big do you really need to print your images? Billboard size?) For a prosumer, I would say get the D700. For a hobbyist or anyone just starting, I think the D300s is plenty good and will still do more than you will probably need for a long time. Save the money on the body and get a couple NICE lenses. Bodies will come and go, but the glass you will keep forever.
An AWESOME combo would be the D300 with the 24-70mm lens plus the Tamron 90mm macro or the Nikon 105mm macro. The 24-70 would be a nice walkaround lens. It's one of the very best lenses nikon makes and it will work well if you later want to upgrade to a full frame camera. On the D300 it would be more like a 35-100mm lens so you lose a little on the wide end but gain on the long end. Or get the Nikon 17-55 DX lens. This will give you more like a 26-82mm range, so you get some of your wide end back. Still a really good lens. But DX lenses don't play well with full frame bodies so if you upgrade in the future you will need to replace that lens. Something to keep in mind with cropped sensors. Not sure if Canon has DX equivalent lenses or not.
Catherine also has a very good point. Think about what you are going to be shooting and what you want to do with these shots. If most of your pics are going to be for posting in the interwebs, this is another good reason to save some moo-la. A higher priced camera might have a little more detail or less noise, but it's not going to make anyone a better photographer. I have shots from my Nikon D70 (6mp/cropped sensor) that I could put next to shots from my D700 and you wouldn't know which was which.