I just picked this up yesterday and I must say that it's a perfect fit for the reader. It's got a good amount of padding, and will undoubtedly work well with any of the covers.
The only thing I didn't like is that the strap on the outside is sewn on at one end (and clipped on the other), so you can't temporarily remove it. Even so, it does tuck in decently inside, so it's not that big of a deal.
At only 12 bucks, this case is well worth picking up even if you don't need or want one.
edit: The colors I've seen are: Vibrant White, Bright Blue, Black, and Pink (the pink one had a nice single-color image of Mario in darker pink)