I've been retweeting some of this stuff on the wiki's twitter feed, but for the benefit of those not following that: Rare employee and DKC lead designer Gregg Mayles has recently posted on his twitter account a lot of development documents for the original Donkey Kong Country, and it's stuff that's never been out in the public before. These includes rare renders, concept art, faxed pictures by Shigeru Miyamoto, and most interesting of all, a design document for a very early incarnation of Donkey Kong Country!
There's more where that came from.
There's more where that came from.