Problem is, didn't a lot of the Rare talent leave at some point. Is it the same 'people' that made Conker etc?
"Chief of ideas" Gregg Mayles - still at Rare
"Other ideas" George Andreas - left for Sony
Lead programmer Chris Sutherland - still at Rare
programmer Morten Brodersen - left Rare long ago
programmer Paul Machacek - still at Rare
programmer Graham Smith - don't know, probably left Rare after Starfox Adventures
programmer Kieran Connell - still at Microsoft, though I think not at Rare
programmer Rhys Lewis - left for Retro Studios (where he is not anymore)
programmer Mark Wilson - don't know, probably left Rare
"Chief scribbler" Steve Mayles - still at Rare
"Catoony bits and more scribbling" Ed Bryan - left Rare for Creative at Nosy Crow
"Scene Crayoner" Steven Hurst - left Rare for Flippin Pixels
"More Sketching" John Nash - credited for Micky Epic 2, so most likely not working at Rare
"Other Doodling" Chris Peil - left Rare
music Grant Kirkhope - freelancer, could probably be hired for new Banjo music
Rest is business and test players. The major losses from the Banjo-team are probably Kirkhope and Hurst (I guess Scene Crayoner means level designer), but considering the small team size of the Banjo team, there still is a lot of potential left for a nice follow-up (especially considering the Mayles brothers are still there), provided they were motivated for it.