It varies from what i had experienced with the 2 units.
The original one came up within 3 days of usage.
First saw it on 4 night shots. Camera just booted up and not even
warmed yet (apparently from what i've read, cameras are more likely
to get stucked or even hot pixels by high temperatures, aka heated
up during usage, humid weather, etc.)
The 2nd one only exhibited the same problem about a month later.
Personally, this camera starts to feel really warm to the touch about
after 10-15shots or several minutes of continuous usage.
The key is doing long exposures.
And once the stucked pixel is there, its there for good. You either have to get it remapped at the service centre (free until end of the 1yr warranty) or like what most users do
1) correct via photoshop (lifecycle of imaging),
2) choose to ignore and live with it (eg. because maybe it isnt major enough to visually affect the pictures).
But overall, manufacturers recognise this as a problem and it is warranted for service/exchange depending on severity.
Even with that said, some users do not have this problem for the life of their equipment (doing super long exposures, eg. 2-5minutes)