No it's clearly not one of those... you can see in the close-up that it appears as a small '+', and there's a smudgy horizontal section below it. I've seen plenty of dead/stuck pixels in my time, but nothing like this. I'd almost think something had hit the monitor, but I know that hasn't happened. It's appeared overnight as I'm sure it wasn't there last night, as I was on my computer for a good few hours and I'm sure I'd have noticed given it's virtually in the middle of the screen.