I don't mind too much on brand, I picked Canon because I could afford a 300D kit that Jessops were doing here in the UK: body, grip a couple of batteries and 18-55 USM kit lens. With the grip it was a nice comfortable handful. But so was the equivalent Nikon and Pentax. Having shot Pentax film cameras I might have gone with them, but in the end came down to price. I could afford the 300D, with enough left over for a tele zoom, the dreaded 75-300 USM III, a tripod, bag and a 1GB CF card. All in at £1000, IIRC none of the other bodies made it below that price, so the 300D had a big advantage.
I have to say that now I do have an ergonomics preference and that is for the bodies with the joystick style interface. I remember when looking to upgrade from my 300D when the 60D first came out and going into a store to look at it and the 7D. I found the 7D to be incredibly intuitive and obvious how to operate the various functions. The 60D on the other hand seemed like a forced kludge of the XD and XXXD interfaces, offering the worst of each. I didn't end up with a 7D but did get in turn a 20D and 50D. I also really dislike SD cards, since I only seem to need to touch the contacts to kill one. Apart from a duff from new card I have, touch wood, never had a CF card fail. I still use that original 1 GB Jessops brand card that came with the 300D in my 20D if I need a second camera. I also tend to use the PC socket quite a bit in situations where I am working with my studio flash kit in an industrial unit with a huge amount of RFI that makes the RF triggers unreliable.
I also have one other requirement for any camera, and that is that it has an OVF. I know EVFs have made great improvements, but I still just really prefer an OVF, especially in a larger camera such as a DSLR, as I often shoot fast moving subjects with very long focal length lenses. Having had a play with one at a show I do have a preference for a smaller body too, but it could only ever be a second system for me, since 135mm is at least 465mm too short. I doubt I'll ever afford one but a Leica M Monochrom with 35, 50 and 90mm lenses would be rather nice. Or maybe a little more realistically the Fuji with the hybrid OVF/EVF system. But for a second system it's still way over my potential budget.
Alan