Is mining bad for the CPU? I've started to mine some Primecoin on a couple of spare VPS's, and it's turning out to be profitable. I'm also mining a bit on my laptop when I'm not using it (e.g. during lunch break).

Will mining wear down (or have any other adverse effects on) the CPU over time? Does the number of cores used during mining (I'm using 2/4) affect this at all?
Its mostly the heat...if it is running quite hot, which most laptops tend to do, it IS damaging the CPU. Try a good cooling mat if you really want to do it.
Also, using 2 of 4 cores WILL run cooler than using all 4. But I guess I could repeat everyone else' advice: "Mining is no longer profitable on the CPU, don't do it." (Even though I do a little bit.)