In this thread, I will keep track of the updates for MKDS:GKE. I will start with the latest update, 1.2.

Version 1.2 added:

• Bignana: replaces Cucumber. Bignana is a track specialist: in fact, in Yoshi Falls, this kart can use the waterfalls as cannon, to skip entire portions of the track. This aside, Bignana offers to you 100 frames of Mini-Turbo boost, the best handling in the vanilla game and an average speed and drift.
• Golden Musher: replaces Mushmellow. Golden Musher really is a giant Golden Mushroom. In all senses: it knows exactly how you would use mushrooms. To cut off-road. Yeah. Golden Musher knows that. In fact, Golden Musher will bring you to the speed of light if you off-road. Yep, off-road now feels like a zipper on steroids. However, this comes with a cost: 49 frames of Mini-Turbo and extremely low speed on-road. But hey, tracks like Desert Hills or GBA Sky Garden should end up being very fun to play nonetheless!