Please add an ebuild for x2godesktopsharing, probably by a USE flag on net-misc/x2goserver as it makes the server functionality more complete.
Summary what x2godesktopsharing does:
x2goserver provides running a new session from remote only, while x2godesktopsharing running on the WM session of a user is additionally adding a notification icon to the tray (notification area in Xfce) that allows remote users to attach to the running WM by accept/deny dialog.
I'd really like to see that feature, too.
This feature is missing yet.
Created attachment 648696 [details]
Ebuild for x2godesktopsharing
Created attachment 648698 [details]
acct-group for x2godesktopsharing
Created attachment 648700 [details]
acct-user for x2godesktopsharing
Published my ebuilds containing this here