Can't pinpoint why it is but I have a niggling feeling that I should be buying a Canon.. spent so long looking at Nikon that I'm not sure about the intricacies of the brand though!
Has there ever been a pole about who has bought into which brand?
No but they are both market leaders, think Canon is bigger although its lost a lot of ground recently with Nikon catching up in the digital world. I'd say its pretty split on here, although there are lot of Nikon owners as the entry level Nikon gear is great value for money.
As said go to a store, borrow a mates or something and see what suits you better. Look at future lenses you may buy, will they work on the D40/D60 etc.
If that 30D refurb goes for sub 300 notes it'll be a steal, as new with a 1 year warranty for semi-pro gear. It just needs a better lens on it but you can get by with the kit lens.