Would be nice if 2.0 also could support the XZ-format (.xz, .tar.xz, .txz), successor of the LZMA-utils <http://tukaani.org/xz/>. While still marked as beta it's already supportet by gnu tar 1.22 and AFAIK XZ-utils are backwards compatible with LZMA-utils and could replace the lzma part.