Hi
I've had my X-Pro1 for over 2 years and I am very happy with it.
I'm generally in agreement with the wish lists noted here, though I am really hoping for minimal changes. I'd like to see updated control layout based on lessons learned from other X series, faster operation, colour focus peaking and a few software tweaks. More mp are OK as long as this doesn't reduce the outstanding quality and feel of the sensor.
The one thing I do not want is a smaller camera. I don't see any advantage, and some strong disadvantages. The X-Pro1 is small and yet not cramped. I do not have large hands, but I find that the obsession over size has produced cramped cameras. I like a small and light system too, but it's the overall system (camera and lens) that matters to me and a few mm shaved from the camera won't make much difference.
But, if they make it smaller without compromising the feel and action, I'll be fine.
I won't rush to upgrade. I have zero issues with my X-Pro1.