Mike, when it came down to it I preferred the feel of the Nikon over the Canon (I was looking at the XS, but the XSi is pretty similar in feel).
My fiancee also liked the feel of the Nikon she tried (D80 in her case) and decided that the economical route would be for us to both go for the same brand so we could share lenses, flashes, etc.
I got my D40 on sale from Amazon for about $400 and then added a 55-200mm VR for another $200. Sure, its more expensive than the comparable Canon XS kit, but the feel and interface of the Nikons was more appealing to me.
I would encourage you to, at the least, get to your closest big-box electronics store and hold the cameras you are considering in your hand and get a feel for the menus and controls.
Best piece of advice I saw when I was looking: Any dSLR is going to be capable of taking great pictures so don't let that be your main concern.
Once I started taking pictures with mine I completely forgot any doubts I had about my decision.