I never bought Banjo Tooie... Partly because I heard that it wouldn't tie in with the original...
I must say, I totally forgot about the Ice Key and all the other little mystery items... I remember reading in magazines/internet about possibly ways to connect the sequel to the original... Those were interesting days! I even remember there was one picture that had BT in the N64, with a connector thing on its top, then BK on top of that... That would have been sweet.
I'm gonna go play some more Banjo. Oh ya, and jinjos are ill.