That is the question. Well let me begin by saying, yes, the DS Lite is VERY nice. It's clean, it's pretty, it does well for what it's supposed to do, and it has a decently-cheap price tag.
But, should you go through the trouble of buying this one if you already have an original Nintendo DS?
Probably not. See, the DS Lite may bring alot of new, nice stuff to the table, but it just isn't enough of an upgrade from the last DS to spend the money.
Now, if you don't have a DS yet, then by all means, go ahead and buy the Lite. It has alot of nice features.
1. Bright, vibrant, colorful display. Every color looks how it should. Everything looks gorgeous, and thats the way it should be.
2. 4 Different light settings, ranging all the way from almost original DS brightness, to OMG I'M BLIND!!!!
3. Huge game library. Not only do you have the hundreds, upon hundreds of DS games, but you also have EVERY GBA known to man. Which leads me to this.
4. GBA Slot for backwards compatibility. So those of you who still play GBA and are afraid of making the jump to a DS, fear no longer! The DS Lite has a GBA slot, so every game you cherish can still be played.
5. Beautiful sound. The sounds comes from two speakers on the top half of the unit, and I must say, its quite pretty. Of course there is also a headphone slot, so Moms, don't be afraid your kid will become a nuisance. =D
Now, just like with everything else, there is also cons..
1. If you are used to the DS Phat, the DS Lite will feel ultra small in your hands. Almost TOO small. It's such a big difference between the systems, it almost feels uncomforatable. Of course that is my own personal experience, and that doesn't mean you won't get used to it. I haven't though.
2. Battery life. It lasts, and it lasts, and it lasts some more, ON THE LOWEST SETTING. On the brightest setting, you'll be lucky to have it for even ONE good game session. Sorry, the battery life just doesn't cut it. Now, if you turn the brightness down, obviously it'll last longer.
3. Due to the fact that the DS Lite is so small, GBA cartridges literally stick out i'd say about a quarter of an inch out of the slot. Now, this doesn't get in the way of anything, you can still hold it right, but if you are, say, OCD, like me, then the cartridge sticking out will bug the begeezus out of you.
All around, the Nintendo DS Lite is a nice system. It does what its supposed to, graphics are nice for a handheld, its pretty, vibrant, and the battery life isn't THAT bad. But if you already own a DS Phat, don't go spend the money to upgrade unless you really want to, or unless you have 129.95 just laying around. Now if you are still stuck in the GBA days, then by all means go hog-wild and pig-crazy and have fun.
Update On Apr 16, 2009: This was a question asked of the battery life. The battery life for the highest setting is average around 6 hours, and the lowest setting is 19 hours. =]