Playtonic Games, formed by six former members of Rare who worked on Banjo-Kazooie (and recently expanded to a team of seven with the first non-Rare member), is working on a spiritual sequel to Banjo-Kazooie. The Guardian had the opportunity to visit the studio, revealing the intentions of Playtonic for what is now known as "Project Ukulele".
The developer is fully independent, and wants to continue on that way, although they admit to collaborating with publishers on this project. Ideally, Ukulele Project will be cross-platform, but considering the connection of Banjo-Kazooie with Nintendo, Wii U would make particular sense. If you want to follow the production of Project Ukulele, check out Playtonic's Twitter account.