As per summary, it's long overdue but I forgot about it. Thanks!
Stable for HPPA.
+ 31 Jul 2009; <chainsaw@gentoo.org> libarchive-2.7.0-r1.ebuild: + Marked stable on AMD64 as requested by Diego E. 'Flameeyes' Pettenò + <flameeyes@gentoo.org> in bug #270679. Compiled-tested on a Core2 Duo with + USE="bzip2 lzma zlib -acl -static -xattr".
x86 stable
lpha/arm/ia64/sh/sparc stable
ppc stable
ppc64 done
bsd has no stable, closing