The Cherokee Nation has voluntarily dismissed their claims against the feds in Cherokee Nation v. Nash:
Cherokee nation vs nash order 8 21 2012 feds
The feds have an outstanding counterclaim against the Nation and so they remain parties.
In the D.C. Circuit appeal, Vann v. Interior, here is Vann’s reply brief:
2012-08-30 Reply Brief of Appellants Marilyn Vann et al
Prior briefs are here.