How to get notifications for package updates
You can just install salix-update-notifier with gslapt or using slapt-get:
slapt-get -i salix-update-notifier
That will run a service that will check every now and then for package updates in the background and will display a system tray notification icon when there are package updates available in the repositories. By clicking on it, gslapt will be launched directly in upgrade mode where you can review the package upgrades and agree to apply them or not.
The salix-update-notifier package is already installed in a full mode installation of Salix.