Maybe some Rare ware characters could be included in the third party lineup. Rare Has created some of the best games that Nintendo Consoles have ever seen, including reviving the Donkey Kong franchise with the Donkey Kong Country Series.
Here's my list of possible characters: Banjo Kazooie; Juno,Vela,and Lupus(Jet Force Gemini); Joanna Dark(Perfect Dark); Rash,Zitz,and Pimple (Battle Toads); Mr. Pants; and finally, the ever so inappropriate Conker the squirrel.
Nintendo and Rare Probably had the strongest relationship in the industry during the SNES/N64 era. There may be some problems with licensing due to Rare being owned by Microsoft. Here's to hopes and Prayers.