When my battery dies I won't get it replaced. I'll simply mount it permanently in a wall with 24/7 power connected and let it do more mundane tasks. I've already gotten my money out of it in enjoyment.
That sounds like a good idea and I can't say it's never crossed my mind although, you would be tethered to the wall all the time and thus defeating the purpose of have a portable/mobile tablet computer. And i'm almost sure that having the iPad plugged in all the time could ruin it over time or damage it in some way.