Can I use my oven for sous-vide I have an electric oven which has a temperature setting, starting at 50c and goes up in 5 degree increments; [50,55,60,65,...]. It also has a fan to circulate air. (pictured below)

Will this be accurate/stable enough to do sous-vide? I'm asking about modern domestic electric ovens in general as opposed to my particular brand (whirlpool).

If I put my bagged meat in to a pot of, say 65deg water, and put it in the oven set for 65deg. Will the water ever get more than a degree or two above 65? 

I suspect that even if the oven fluctuates +-10deg, the thermal mass of the water won't allow it's contents to fluctuate in temperature change so much, assuming of course that the oven will average at 65deg.

Has anyone tried sous-vide with their oven, or are the thermostats so inaccurate that it not likely to work?
Accuracy of the temperature is going to vary by oven, so there's no definitive answer there. As GdD said, you'll just have to get a thermometer and try it. 

However, I think this will probably work fine for most sous vide applications. While sous vide is all about precision, a couple of degrees fluctuation isn't going to make a huge difference for most preparations (eggs are a notable exception), particularly given the thermal mass of the water. You could also throw a pizza stone or something in the oven too to help keep a more constant temp.