Originally posted by i83N ... hardware update will be just new sensor ...
Since the mark 2 just came out, we're more than a year away from a theoretical mark 3, and by the time that happens technology will advance so the upgrade needs to be be more than just a sensor. I'll play along, though:
Improved dynamic range and low-light performance, even with the same pixel count, could get me to upgrade for low light and astrophotography.
If just more megapixels then no I would not upgrade. A higher pixel count would be useful for wildlife cropping, but IMO that would also have to be accompanied by upgraded AF plus improved shutter mechanism for less shutter shock.