I wouldn't say that I *want* it, per se, but I would agree that such a scene is very plausible, particularly if Jack's operating on incomplete information when he and the Doctor meet again.

I don't think Jack would be jealous of another assistant on the scene - he's not the jealous type - but he might resent how quickly the Doctor "replaced" Rose (if Jack gets that data, that is)

There was a nice bit in one of the BFAs - it was either "Neverland" or "Scherzo", probably the former - in which the Doctor mentions certain speculations as to why he tends to travel with people, particularly non-long-lived folks. It's quite neat, but I don't want to spoil it for you. :)