I guess am easy solution would be to add a language field in the table that stores the article news info and then filter results according to site laguage set by user.
As for a default function to be implemented by Boonex in the next release, I'd look at how Netlog manages languages in users' profiles.
Below is the legacy version of the Boonex site, maintained for Dolphin.Pro 7.x support.
The new Dolphin solution is powered by UNA Community Management System.