Ok... How much DS do you play in a day? It's like an IPod... people complain that the battery sucks, but it only sucks if you use it for the entirety of a 12 hour flight (SLEEP NEXT TIME).
I know it's convenient to not deal with it, but it's not anything close to crippling. I set it to charge when I go to bed, and it's never hard to play while it's connected to the charger at home. If I'm traveling, I can charge it during a layover, at a hotel, or in any bar/cafe I go to. Sure, 4-5 hour battery life is short of normal, but if it's a problem, you've probably got a bigger one somewhere along the line...