As matters arising from my joint paper with G. Tang, " Higher K-theory of group-rings of virtually infinite cyclic groups" Math Annalen 325 (2003) 711-725, I am curious to know if anyone has since proved that the Nil groups of Bass and those of Waldhausen are isomorphic for all n > 1. Such an isomorphism is well known for n less than equal to 1 and we used it to show the vanishing of lower Waldhausen nil groups for regular rings.
Article Higher K -theory of group-rings of virtually infinite cyclic groups