Botan 1.10.3 is the latest stable release. It fixes botan-config-1.10 so that it outputs proper cflags, which is related to bug #380481.
Botan 1.10.3 with compatibility symlinks (botan-config, botan.pc) and support for Python 3 has been available in Progress Overlay since 2012-08-11.
Arfrever - the progress overlay update looks good to me.
Bumped, simple ebuild copy, not solving bug#380481 slot issue.