Hello I would be very glad if p7zip support would as well be added, since it is just a small change, and doesn't hurt anyone. Personally and for the environments I run Debian, using bz2 is not of any advantage to me. I have done some statistics of the advantages of several compression software of the i386/linux Debian archive here (I also think rzip is interesting):
http://www.linuks.mine.nu/sizematters/ Please support p7zip. Yours, Gürkan