Don't expect the same treatment for the Fire though. They're already losing out on enough money by selling it to you for cheap! You can't feel the Kindle 3 under you when you sit on it, but the Fire is thicker and has a better long lasting screen. It'd be like sitting on a flat screen.
And personally, I would be really disgusted if Amazon was replacing Kindle Fires that the little kids are breaking and/or drooling all over. Mostly because it's more the customer's problem than it is theirs.
Battery problems, headphone jack not working, speakers busting (to an extent, you can't expect a tablet to work like an amp, dumb move period), and drive failures are real issues. Not that your kid has decided to try and draw pretty pictures all over it or sat on the screen.
People need to accept wear and tear, and they need to accept that just because your device breaks doesn't mean it's the fault of the person who sold it to you.
And if I was an Amazon shareholder, I'd be pretty mad to see all my money going into Kindle replacements.