For people who use the Co-Author Plus plugin, now there is a way to display the profiles of all the co-authors on the sidebar of the Single page using the Author Spotlight (Widget). This support was added in 2.0 release of the widget. Hope you will find it useful.
Erlend, I am using the Co-authors plugin (2.1.1) on 2 of my blogs on WordPress 3.0.1 and I did get this message as well during plugin activation. However, I didn’t see any other issues after that. My sites and all other plugins (including the Co-Author plus and Author Spotlight) work fine.
I suppose so. It’s just that I wouldn’t really ever feel 100% comfortable having that plugin around as long as it produces that error. Every time something goes wrong with my site I’m gonna have this urge to fail-check that plugin first, even when there are much more likely culprits.