Surprisingly, I've never had the numbers/letters rub off of any of my keys, and I've been using the same keyboard for about 10 years. Of course, by taking a look at the way I type, it appears that my fingers rarely come in contact with the letters. I almost always hit to the right side or the bottom.
As for my mouse...I've only had it for two or three years, I think, so not much wear there either. However, I can see a smooth area where my finger goes, so perhaps the plastic is just a solid color rather than being painted.
If you want a keyboard that doesn't wear out, you could always get one of those laser-projection keyboards. Of course, knowing you, you'd probably wear out the wood on your desk. Heh.
