We have information from Nintendo Power's interview on Mario Kart DS.
Features
-Over 30 courses
-Approximately half of the courses are new
-8 Player Single-Card download play
-4 Player online mode via Nintendo Wi-Fi Connection
-You can choose the same characters in Multiplayer mode, for example, everyone can be Mario but you will be able to tell the difference because of the players names over the karter's head.
-Battle Mode is available
-Computer A.I is improved
-Battle Mode is available online, but no co-op play
-The Touch Screen can be used to draw decals on your karts (no doubt parts of the body)
-Possible touch-control steering
-The DS features will be used, Hideki Konno said they wanted to make a Balloon weapon where you blow on the microphone to blow the balloon up
-The feather item from Super Mario Kart is being considered
"In our interview with Hideki Konno yesterday, the producer of Mario Kart DS gave us new details on the game's online mode and updates to the weapons and battle mode. He says the theme of the new Mario Kart is an expansion of the multiplayer and community aspects that the series is known for. The LAN mode is the ideal form of multiplayer, because up to eight players can compete (on a single game card), and the gameplay is locked in at sixty frames per second. The online WiFi mode supports four players, and the team is working very hard to achieve the same framerate as with LAN mode, but they aren't there yet. In a first for the Mario Kart series, players will be able to choose the same character simultaneously, so you can have a race of eight Marios. Individual players are still identifiable during the race, because the registered DS system name will be displayed above each player's character.
Mario Kart DS aims to be the biggest MK game yet, with over thirty courses and approximately half of those being brand new. The rest are courses ported from previous Mario Kart games, chosen for their nostalgic appeal. Battle mode is returning and is more or less the same as in past games, but the computer A.I. is being enhanced so that the mode will be fun even for a single player battling against bots. Additionally, Mr. Konno said the battle mode will probably be enabled for online play, as with the racing gameplay. Since all the karts in MKDS are built for just one character, there is no cooperative mode like the one found in the GameCube's Double Dash.
Although the game will be extremely familiar to fans of the series (don't expect any huge changes to the way it plays), Mr. Konno's team is looking at several ways to use the DS input features. The touch screen can be used to draw custom decals to decorate your favorite kart, and touch screen steering is being considered (though it would probably be optional, as the E3 demo is played entirely with the D-pad and buttons). As for weapons, the team would like to implement some new items that use the DS features, such as a balloon that is inflated by blowing into the microphone. By the way, we asked Konno-san about the feather item, and he said that he would keep it in mind."
