Hardware Redesign: The DSi has been overhauled inside and out. The new portable is 12 percent thinner, slightly longer and has a smudge-resistant matte finish. The DSi also has redesigned speakers, slightly larger, slightly more crisp screens, and a volume button that can also adjust screen brightness on the fly.
More importantly, the DSi sports a CPU clocked at 133 MHz, as opposed to the DS Lite's 66 Mhz, and with 16 MB of RAM has four times the RAM of its predecessor.
Cameras: There are two .3 megapixel VGA digital cameras built into the DSi, one on the internal hinge pointing at the gamer and the other on the top right corner of the case, pointing at the world. The cameras aren't fantastic, but they can be quite a bit of fun for playing around with images.
SD Slot: The ability to slap any SD card into the DSi for storing or transporting games, audio and pictures is a big plus for this system. It means you won't have to worry about running out of space when you start snapping pics or downloading games. It also offers plenty of opportunity for things like a video download service in the future.
Interface: The DSi's sports a slick interface that you can use to quickly hop around in the system with and personalize. The top screen can display an image you take with your DSi and the bottom screen is a row of icons that can be moved about. As you download software, more icons appear. When you pop a game in the DS slot, that game appears as well. The best part is that I have yet to have to restart my DSi after going online or playing a game, you just tap the power button to return to the home screen.
DSi Store: The ability to purchase and download games on the fly with your DSi is the main reason I wanted this portable. Sure, the initial offering is surprisingly weak, but it can only improve over time. And I'd be surprised if they didn't start offering retro titles for the store as well. I also love that I can buy points for the system without having to leave the store.
GBA Slot: The biggest problem with the DSi is that it puts a bullet in the head of the Game Boy Advance. Sure, Nintendo might (read: should) start selling GBA games as downloadable titles down the line, but if you already have a bunch, that isn't going to be much consolation. Worse is the fact that nifty add-on controllers, like the one for Guitar Hero: On Tour, which use the GBA slot, will be useless if you pick up a DSi.
Photo Sharing: I love the idea of the cameras and the software, while super gimmicky, can be quite a bit of fun to play around with, even for adults. But not being able to import images taken from anything other than a DSi and not being able to send your photos to a cell phone or a PC is inexcusable.
While images can be loaded onto an SD card, Nintendo makes no claims about whether you'll be able to actually view edited images once you plug that card into a PC. When I examined an SD card with pics saved on it I was able to find the files, each about 35 KB JPEGs. It would be great, though, if they took a couple of steps out of the process and let you send email them or send them to a phone.
Nitpicks: In general, the DSi is a solid piece of equipment. It does, however, have quite a few irksome issues. The DSi's battery life is one to ten hours shorter than the DS (depending on use). The charger for your DSi is, once again, designed only for the DSi. Pictochat remains unchanged and is still missing the ability to go online. And the free downloadable web browser is painful to use, doesn't support Flash and quickly runs out of cache space.
Overall, the DSi is a great upgraded version of the DS Lite, but I feel they could have done a better job compared to other portable game systems. Definitely I want the DSi sooner or later, but I am going to wait until the second generation of DSi comes out. Hopefully, it comes out with better features.