Today I've updated my Gentoo Nessus ebuilds to the just released version 4. Since the official maintainer of the Nessus ebuilds for Gentoo is very slow with updating, I've submitted the updated packages to the sec-tools overlay. At the moment they are not available yet, but I expect them to become available very soon.
If you can't wait you can also grab the ebuilds for both the server and the client from this Gentoo bug report. Unlike the previous versions this version of the service package does not include any plugins anymore. So in order to do something usefull with it you have to register either a Professional or Home feed at Tenable and fetch the newest plugins once installed.
Please let me know if you encounter any problems and leave a comment here or at bug id 265555.