Ron Rennick

The WP/WPMU author link from the <code>the_author_posts_link()</code> template tag on the blog will link to the author’s buddypress member profile instead of the author’s posts page.
This plugin will only affect blogs where buddypress is activated sitewide. It will function the same in either the mu-plugins folder or in the plugins folder and activated sitewide.

BP Blog Author Link

This plugin changes the blog author links on a buddypress site to link to the author's buddypress member profile.

Konstantin Obenland

This plugin lets users specify a unique autor description for each individual site in a network. It falls back to the description of the primary site when no specific description is set.

WPMU Author Description

Specify a unique autor description for each individual site in a network.

BP Blog Author Link vs WPMU Author Description